Flexible 64 Ã 64 Pixel AMOLED Displays Driven by Uniform Carbon

Subscriber access provided by LUNDS UNIV

Functional Nanostructured Materials (including low-D carbon)

Flexible 64 × 64 Pixel AMOLED Displays Driven by Uniform Carbon Nanotube Thin-film Transistors Tian-Yang Zhao, Dingdong Zhang, Ting-Yu Qu, Lin-Lin Fang, QianBing Zhu, Yun Sun, Tian-Hong Cai, Maolin Chen, Bing-Wei Wang, Jinhong Du, Wencai Ren, Xin Yan, Qingwen Li, Song Qiu, and Dongming Sun ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.8b17909 • Publication Date (Web): 06 Mar 2019 Downloaded from http://pubs.acs.org on March 6, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

Flexible 64 × 64 Pixel AMOLED Displays Driven by Uniform Carbon Nanotube Thin-film Transistors Tian-Yang Zhao1#, Ding-Dong Zhang2,3#, Ting-Yu Qu2#, Lin-Lin Fang4, Qian-Bing Zhu2,3, Yun Sun2, Tian-Hong Cai1, Mao-Lin Chen2,3, Bing-Wei Wang2,3, Jin-Hong Du2,3*, Wen-Cai Ren2,3, Xin Yan1*, Qing-Wen Li5, Song Qiu5, Dong-Ming Sun1,2,3*

1College

of Information Science and Engineering, Northeastern University, 3-11 Wenhua Road, Shenyang, 110819, China.

2Shenyang

National Laboratory for Materials Science, Institute of Metal Research,

Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, China. 3School

of Material Science and Engineering, University of Science and Technology of China, 72 Wenhua Road, Shenyang, 110016, China.

4Wuhan

China Star Optoelectronics Technology Co., Ltd., 8 Zuoling Road, Wuhan, 430078, China.

5Suzhou

Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 398 Ruoshui Road, Suzhou, 215123, China.

KEYWORDS: Carbon nanotube, Thin-film transistors, High uniformity, Flexible, AMOLED

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ABSTRACT Carbon nanotube (CNT) thin-film transistors are expected to be promising for use in flexible electronics including flexible and transparent integrated circuits, wearable chemical and physical sensors, and driving the circuits of flexible display panels. However, current devices based on CNT channels suffer from poor performance uniformity and low manufacturing yield, therefore are still far from practical. This is usually caused by nonuniform deposition of the semiconducting CNTs and rough surface of flexible substrate. Here we report a flexible 64 × 64 pixel CNT thin-film transistors (TFTs) driving active matrix light-emitting diode display (AMOLED) driven by improving formation of uniform CNT films, and developing a new pre-treatment technique for flexible substrate. The achieved AMOLED has uniform brightness and a high yield of 99.93% in its 4096 pixels. More than 8000 TFTs with high-purity semiconducting CNTs as the channel material show an average on-off current ratio of ~107, a carrier mobility of 16 cm2V−1s−1. The standard deviations of the on-state current and the carrier mobility are 4.1% and 6.5%, respectively. Our result shows that panel driven by high-purity semiconducting CNTs is a promising strategy for the development of next-generation flexible large-area displays.

INTRODUCTION Flexible active matrix organic light emitting diode (AMOLED) technology has attracted considerable attention because it can meet the needs of future display diversity. Representative materials including polysilicon, organic and oxide semiconductors are currently used as channels for thin-film transistors (TFTs) in driving circuits, however, they usually exhibit relatively low carrier mobility and poor stability, and cannot effectively drive large-area and high-resolution flexible AMOLED.1–3 Carbon nanotubes (CNTs) have attracted great attention for applications in flexible and wearable electronics including flexible and transparent integrated


Page 2 of 20

Page 3 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


circuits,4–11 chemical and physical sensors,5,9,12–16 and flexible non-volatile memories,17–19 owing to their exceptional properties including extremely high electrical conductivity, optical transmittance, mechanical strength, and flexibility.20–23 In particular, recent progresses have been made in driving circuits of AMOLED display panels.9,24–26 Zhang et al. first fabricated a CNT TFTs-based AMOLED driving circuit with 20×25 pixels on a hard substrate, and successfully lit up the AMOLED matrix. However, the device yield was only about 70%, and a considerable part of the pixels was not working properly. Zou et al. realized the dynamic display of the AMOLED driving circuit based on the CNT TFTs on a hard substrate, but their pixel integration only included 6×6 pixels. Both of above results showed that the uniformity of the light emission of the pixel was poor, and the distribution of the luminous intensity was quite different. Such unsatisfactory pixel integration level, yield and brightness uniformity lead reported devices to being far from practical.9,25,27–30 The main challenges are: a) nonuniform performance of CNT TFTs in the subthreshold region resulting from the inhomogeneous film morphology of CNTs in the channels; b) performance degradation of the OLED caused by serious surface roughness of flexible substrates. In our previous work, we have demonstrated an optimized process for improving the quality of semiconducting CNT solutions and films by removing the free dispersant polymer.29 Here, a certain content of residual polymer on the CNTs ensures dispersion stability and facilitates the formation of high density and uniform CNT films. We also report a new technique for the pre-treatment of the flexible polymer substrate to achieve a significantly smooth surface to improve the yield of CNT TFTs and OLED pixels. Based on the above two key innovations, we achieve a highly-uniform array of CNT TFTs, and demonstrate a flexible 64 × 64 pixel AMOLED driving circuit with a high on-off ratio, a uniform threshold voltage and off current, capability in deformable condition, and a high integration level, that worked well when deformed. This is the best performance of CNT-based flexible AMOLED displays currently.



RESULTS AND DISCUSSIONS High-purity (>99.9%) semiconducting CNTs were used as the active channels of TFTs. New solvents, including tetrahydrofuran and chloroform, were helpful in obtaining clean CNTs with a minimum amount of polymer entangled around them. A polyethylene naphthalate (PEN) substrate was pretreated at 190 °C for 3 h to maximize its stretchability and then soaked in the solvent of Remover-PG to remove the heating-generated particles (For details, see Method). A control circuit for a single OLED pixel consists of a switching transistor (Ts), a driving transistor (Td) and a capacitor (Cs). Figure 1 shows the characterization of a buried-gate switching transistor (Ts) and a driving transistor (Td) as the basic components of a single pixel circuit. The channel length (L) and width (W) of Ts are both 30 µm, while those of Td are 30 and 90 µm, respectively. A scanning electron microscope (SEM) image (Fig. 1b) shows the morphology of the CNT film to be highly uniform with an average CNT length of 2 µm. SEM images taken at different locations on a 4-inch substrate show that high-density, uniform CNT thin films were obtained (Fig. S1). An atomic force microscope (AFM) image (Fig. 1c) shows that the thickness of semiconducting CNT channel is ~6 nm. Figure 1d shows the transfer characteristics of Ts and Td, showing similar p-type characteristics with an on-off current ratio of ~107 and a three-fold difference in the on-currents. The carrier mobility was evaluated to be approximately 16 cm2V−1s−1 by a standard method, which is high enough for use in the driving circuits of an AMOLED device.30,31 Figure 1e shows the output characteristics of the same Ts and Td with VGS increasing from −5 V to 0 V in steps of 0.5 V. The maximum on-currents of Ts and Td are 2.4 and 9.7 µA, respectively, at VGS = −5 V and VDS = −3 V.


Page 4 of 20

Page 5 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 1. Characterization of the switching and driving CNT transistors. (a) Schematics of a buried-gate thin-film transistor. (b) SEM image of the CNT channel (scale bar, 1 μm). (c) AFM image showing the morphology and thickness of the CNT channel (scale bar, 1 μm). (d) Transfer characteristics of Ts and Td. VDS = −1 V. (e) Output characteristics of Ts and Td with VGS values from −5 V to 0 V in 0.5-V steps. Figures 2a and 2b show the electrical performance of a single pixel driving circuit. The switching transistor (Ts) is turned on at VSCAN = −5 V and VDD = 1 V, and the current flowing through the driving transistor (Td) can be adjusted for an on-off ratio of 107 by changing VDATA. A maximum output current of 7.7 µA is achieved at VDATA = −5 V and VDD = 3 V. Even though there is a difference between the experimental result and the simulation result obtained by using PSpice Model Editor in Cadence software since the bipolar characteristics had not been taken into account, the simulation is helpful for the evaluation of the current control capability of a single pixel driving circuit for circuit design. The performance uniformity of driving circuits is crucial for achieving a large-area AMOLED display. Figure 2c shows a statistical analysis of the electrical



performance of driving transistors in 60 pixels as an example of the evaluation. The device yield is 100%. The average on-current is 7.5 µA and the off-current distribution is in the pico-ampere range. The standard deviations of on-current and mobility are 4.1% and 6.5% of the average values, respectively. The average threshold voltage (VTH) is −1.39 V, and its standard deviation is 4.2% (Fig. S2). The performance of our CNT driving circuits shows small pixel-to-pixel variations compared with other CNT-TFT devices in the literature,9,14,24,32,33 where the standard deviations of the reported VTH, on-current, and carrier mobility are 145.5% to 3%, 36.1% to 8.3%, and 37.9% to 10% respectively (Table S1). The device also exhibits the possibility of working well in a deformed condition. Figure 2d shows the transfer characteristics (IDD-VDATA) of a single pixel driving circuit under bending conditions of 0.1%, 0.2%, 0.3% and 0.4%. The on-current and off-current show little changes even for a bending strain up to 0.4% (radius of curvature, 15.6 mm), demonstrating the excellent reliability of the driving circuit under a large deformation (Fig. S3 and S4).


Page 6 of 20

Page 7 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 2. Characterization of the circuit for a single AMOLED pixel. (a) Transfer characteristics of a single pixel device at VDD = 1 V and VSCAN = −5 V. (b) Output characteristics at VSCAN = −5 V with VDATA changing from −5 V to 0 V in 0.5-V steps. (c) Statistical distributions of on-current, off-current and threshold voltage of 60 devices. (d) Transfer characteristics at bending strains from 0.1% to 0.4% at VDD = 1 V and VSCAN = −5 V. Aggregated particles produced on the PEN surface during heat treatment usually lead to a large roughness. We developed an effective method to reduce the surface roughness in the driving circuits leading to an ultra-high yield of AMOLED, which surpasses previously reported values which were caused by these large particles piercing the OLED materials.24,25 The PEN substrate was pre-heated at 190 °C for 3 h to produce the aggregated particles on the surface, and then immersed in a solvent of Remover-PG at 90 °C for 20 min, followed by thorough rinsing in iso-propyl alcohol (IPA) for 5 min twice, which removed almost all of the particles on the PEN surface (Fig. S5). Figures 3a and 3b show AFM images before and after pre-processing, respectively. The surface roughness in the anode region using the cleansing treatment is 3 nm, which is much lower than that of the untreated sample. Figure 3c shows the morphology of the overlap region between the anode and the driving transistor, which reveals an overall height of 60 nm and a width of 800 nm with a slope of 4.3°. We studied the reason of such gentle slope formed and found that the residual passivation layer remained at the edge of the electrode to form a connection between the insulator and the source/drain (Fig. S6). Such special structure will greatly decrease the slope of the contact edge to avoid the short of the anode and cathode of the OLED to improve the yield of the device.



Figure 3. Characterization of surface roughness. (a) AFM image showing the surface roughness of a pretreated sample. Inset: height profile along the white dashed line. (b) AFM image showing the surface roughness of an untreated sample. Inset: height profile along the white dashed line. (c) AFM image showing the morphology of the region between the anode and the driving transistor. (d) Height profile along the white dashed line in (c). A 64 × 64 pixel AMOLED display panel driven by CNT TFTs and ICs was fabricated on the flexible substrate described above, as shown in Fig. 4. When the scan line (VSCAN) is selected, Ts is turned on to transmit the image information of the data line (VDATA) to Td. The brightness of the OLED can be tuned by adjusting the current flowing through Td. The areas of OLED (SOLED) and whole pixel (SPIXEL) are 185 × 155 μm2 and 240 × 280 μm2, respectively, so the aperture ratio of the pixel is 43% (SOLED / SPIXEL).


Page 8 of 20

Page 9 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 4. Flexible CNT-based AMOLED display. (a) Optical photograph of the fabricated flexible CNT-based AMOLED array (scale bar, 1 cm). (b) Micrograph of the region in (a) denoted by the green box (scale bar, 300 μm). (c) Micrograph of the single AMOLED pixel denoted by the blue box in (b) (scale bar, 50 μm). (d) Circuit diagram of the AMOLED array. (e) Schematics of an AMOLED pixel. (f) Schematic view of the AMOLED layer structure.



Page 10 of 20

Figures 4e and 4f show schematics of an AMOLED pixel and the layer structure of a top-emitting green AMOLED. We evaluated the performance of a top-emitting green OLED device with a lighting area of 16 mm2 on a glass substrate. The bottom anode and top cathode of the OLED were formed by an 80-nm-thick Al layer and a 17-nm-thick Al layer, respectively. The luminance of the OLED was increased by increasing the driving voltage from 0 V to 8 V, when the emitted green light passes through the thin top cathode (Fig. S7). The threshold voltage is less than 3 V. The good electron injection and transparency of the top electrode allowed this standard OLED to exhibit a maximum current efficiency of 50 cd A−1 and a power efficiency of 54 lm W−1 (Fig. S8 and S9). The top-emitting light device showed a brightness in excess of 10000 cd m−2. The 17-nm-thick Al cathode showed excellent light transmittance

and

conductivity,

and

the

identical

peak

position

of

the

electroluminescence spectra obtained at different voltages indicates good stability of the OLED device with Al layers as both electrodes (Fig. S10). We performed a lighting test of the flexible 64 × 64 pixel AMOLED display when deformed, as shown in Fig. 5. Only 3 pixels of the total of 4096 were not lightened indicating a yield of more than 99.93%, which means that more than 8000 transistors in one chip worked well simultaneously. There are several possible reasons for such high yield. First, the fabricated CNT TFTs exhibit a yield of 100% due to the deposited uniform CNT channels. Second, the slope at the contact edge of the windows was effectively decreased to avoid the short of anode and cathode of OLED. Third, a heat pretreatment and a cleaning process was carried out to achieve a much better surface roughness (Fig. S5). It is recognized that there is a possibility to exist a few tiny particles to make 3 pixels were not lighted. The high-quality luminescence of this AMOLED under the bending condition shown in Fig. 5b demonstrates the ability of this device to be used for a flexible display (Supplementary Video). Figure 5c shows the relation between the current density flowing through the OLED and the applied voltage. The current can be effectively tuned to adjust the brightness of the OLED and exhibits good driving ability with a current density of 0.14 A cm−2 at VDD = 12 V. It is also proved that the driving circuit is ready for a dynamic operation


Page 11 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(Supplementary Fig. S11 and S12), where the capacitor (Cs) can store and stabilize image information obtained from the data line during one scan cycle for a continuous and stable image display based on a line-by-line scanning method. Figure 5d shows a comparison of the performance of our device with previously reported CNT-based AMOLED devices in terms of integration scale and yield. Our device has the highest integration level and yield, and exhibits excellent uniformity in the brightness of all pixels, which is attributed to the excellent uniformity of the on-current distribution in the driving circuits.

Figure 5. Evaluation of a flexible 64×64 AMOLED display. (a) Optical photograph of a lighted uniform array (scale bar, 5 mm). (b) Demonstration of the AMOLED chip under bending. (c) Dependence of the current density and the applied voltage. (d) Comparison of our results and other representative AMOLED devices in terms of integration level and light emission yield.



CONCLUSIONS We have produced a flexible 64×64 pixel AMOLED display device driven by CNT TFTs which has uniform brightness and a high yield of 99.93% in a total of 4096 pixels. The driving circuit shows excellent switching characteristics, current driving capability and flexibility. More than 8000 CNT-based transistors in one chip showed a highly uniform performance with deviations of on-current and mobility of 4.1% and 6.5% of the average values, respectively. Our work demonstrates that uniform semiconducting CNT channels deposited from a high-purity CNT solution in an ambient environment are promising for use in future flexible large-scale AMOLED devices.

EXPERIMENTAL METHODS Pretreatment of the PEN substrate. The PEN substrate was pre-heated at 190 °C for 3 h on a hot plate to maximize its stretchability. The substrate was cooled down to room temperature, and soaked in the solvent of Remover-PG at 90 °C for 20 min, and then cleaned in IPA at 90 °C for 5 min twice, and finally dried by a nitrogen blow. Fabrication of flexible AMOLED driving circuits. Gate electrodes (Ti/Au: 5/50 nm) were fabricated by standard photolithography, electron-beam evaporation and lift-off processes. Next, a 30-nm-thick Al2O3 layer was deposited on the substrate by an atomic layer deposition (ALD) technique (precursors, trimethylaluminum and water; chamber temperature, 150 ºC) as the insulator, followed by window opening by reactive ion etching (CF4 flux rate, 50 sccm; pressure, 5.0 Pa; power, 100 W; time, 8 min). Subsequently, the source and drain electrodes were formatted onto the insulator by the aforementioned method. The semiconducting CNTs were deposited on the substrate as the channels (see the next section for details). The unwanted CNTs were removed by oxygen plasma etching (O2 flux rate, 180 sccm; power, 200 W; time, 2 min). Finally, another 30-nm-thick Al2O3 layer was deposited onto the substrate as passivation and the OLED windows were opened using the aforementioned method. Preparation and deposition of semiconducting CNTs. High-purity (>99.9%) semiconducting CNTs were prepared by mixing bulk CNTs (100 mg) with a


Page 12 of 20

Page 13 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


dispersant 9-(1-octylonoyl)-9H-carbazole-2,7-diyl (PCz) (100 mg) in a xylene (100 mL) solution, followed by ultrasonication (Sonics VC500) for 30 min and centrifugation (Allegra X-22R centrifuge) at 45000 g for 1 h to remove bundles and insoluble substances. The CNTs were then filtrated and washed in tetrahydrofuran and redispersed in chloroform29. The supernatant was mixed with toluene in a volume ratio of 1:25 and then ultrasonically treated for 5 min. Before deposition, a plastic substrate (PEN, Teijin DuPont Films, thickness of 125 µm) was heated at 160 °C for 20 min. A monolayer of hexamethyldisilazane (MCC Primer) was spin-coated onto the substrate to improve the surface wettability. Subsequently, the substrate was immersed in the semiconducting CNT solution at 80 °C for 2 h and allowed to settle for 12 h at room temperature. Finally, the substrate was successively soaked in toluene, acetone and isopropyl alcohol, each for 5 min, and then heated at 150 °C for 30 min. OLED Fabrication. First, an OLED anode (Ti/Al: 5/80 nm) and a hole injection layer (MoO3: 5 nm) were deposited on the AMOLED driving circuits. Next, a 60-nm-thick layer of di-[4-(N,N-ditolyl-amino)-phenyl]cyclohexane was deposited as the hole transport layer, followed by the formation of an 8-nm-thick layer of 1,1-bis[4-[N,N-di(p-tolyl)amino]phenyl] cyclohexane (TCTA) and an 8-nm-thick layer

of

bathophenanthroline

(acetylacetonate)iridium(III)

(Bphen)

[Ir(ppy)2(acac)]

doped as

with the

bis(2-phenylpyridine)

light

emission

layers.

Subsequently, another 60-nm-thick Bphen layer was used as the electron transport layer. Finally, a cathode (Li/Al: 1/17 nm) was deposited for the top electrode of the AMOLED. Simulation of a single-pixel driving circuit. The simulation was carried out by using the Model Editor in the PSpice package of Cadence software. First, the transistor models for the transfer and output characteristics were defined based on the measurement results. Next, a single-pixel driving circuit was established in the Design Entry CIS module based on the input models of a switching transistor, a driving transistor, a capacitor, a diode and several connection wires. Finally, the transfer and



output characteristics of the single-pixel driving circuit were extracted at an appropriate scanning voltage. Characterization. The fabricated samples were characterized by an optical microscope (Olympus BX51M) and an SEM (Nova NanoSEM 430, acceleration voltage of 1 kV). The electrical properties of the devices were measured by a probe station (Cascade M150) and a semiconductor analyzer (Agilent B1500A) under ambient conditions. The illumination characteristics of the standard OLEDs and AMOLEDs were measured by a source measurement unit (Keithley 2450) and a luminance meter (Photo Research PR-655) with a calibrated silicon photodiode. ASSOCIATED CONTENT Supporting Information SEM images of the CNT channels taken at different locations on a 4-inch substrate, statistical distribution of the carrier mobility of 60 devices, experimental setup of AMOLED drive pixels on a bent substrate, schematic of a bent substrate, photograph of the surface of a PEN substrate, schematics showing windows for the wires connecting with the OLED, luminance of a standard OLED at different VDATA from 0 V to 8 V, performance of an OLED with an Al top electrode, relation between current density, luminance and the voltage applied to the OLED, electroluminescence spectra at different voltages from 3 V to 8 V, AMOLED measurement setup.

AUTHOR INFORMATION Corresponding Author *Email:

[email protected] (J. H. Du); [email protected] (X. Yan);

[email protected] (D. M. Sun) #These

authors were equal major contributors to this work.

Author contributions


Page 14 of 20

Page 15 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


T.Y.Z., D.D.Z. and T.Y.Q. contributed equally to this work. D.M.S. and J.H.D. conceived and designed the experiments. T.Y.Z., L.L.F. and T.Y.Q. performed CNT transistor fabrication and electrical characterizations. D.D.Z. performed AMOLED fabrication and optoelectronic characterizations. T.H.C., T.Y.Z. and T.Y.Q. contributed to circuit modelling. M.L.C., T.Y.Q., Y.S. and B.W.W. performed materials characterization. Q.B.Z. transferred the CNTs for channels. S.Q. and Q.W.L. prepared semiconducting CNT solution. T.Y.Z., T.Y.Q., and D.M.S. co-wrote the paper. All authors discussed the results and commented on the manuscript.

Notes The authors declare no competing financial interest. Supplementary Information accompanies this paper on the website.

ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (Grants 51625203, 51532008, 51521091, 51272257, 51572264, 51390473, 51502304, 61422406, 61574143, 51371178, 51372254 and 21373262), National Key Research and Development Program of China (2016YFB0401104), the Ministry of Science and Technology

of

China

(Grants

2016YFA0200101,

2016YFB04001104

and

2016YFA0200102), a China Postdoctoral Science Foundation Second-class General Financial Grant (2015M58137), the Chinese Academy of Sciences (Grant KGZD-EW-T06), the Strategic Priority Research Program of Chinese Academy of Sciences, Grant No. XDB30000000, the CAS/SAFEA International Partnership Program for Creative Research Teams and the Thousand Talent Program for Young Outstanding Scientists. X. Y. acknowledges support by the NSFC Grant 61775032, and Fundamental Research Funds for the Central Universities (Grant N160404009). S. Q. and Q.-W. L. acknowledge support from the Key Research Program of Frontier Science of Chinese Academy of Sciences (Grant QYZDB-SSWSLH031) and NSFC



Grant 21373262. The authors sincerely thank Prof. Huiming Cheng and Prof. Peter Thrower for his constructive advice.

REFERENCES (1)

Fortunato, E.; Barquinha, P.; Martins, R. Oxide Semiconductor Thin-Film Transistors: A Review of Recent Advances. Adv. Mater. 2012, 24 (22), 2945– 2986.

(2)

S. D. Brotherton. Polycrystalline Silicon Thin Film Transistors. Semicond. Sci. Technol. 1995, 10, 721–738.

(3)

Sekitani, T.; Zschieschang, U.; Klauk, H.; Someya, T. Flexible Organic Transistors and Circuits with Extreme Bending Stability. Nat. Mater. 2010, 9 (12), 1015–1022.

(4)

Zhang, D. H.; Ryu, K.; Liu, X. L.; Polikarpov, E.; Ly, J.; Tompson, M. E.; Zhou, C. W. Transparent, Conductive, and Flexible Carbon Nanotube Films and Their Application in Organic Light-Emitting Diodes. Nano Lett. 2006, 6 (9), 1880–1886.

(5)

Lipomi, D. J.; Vosgueritchian, M.; Tee, B. C. K.; Hellstrom, S. L.; Lee, J. A.; Fox, C. H.; Bao, Z. Skin-like Pressure and Strain Sensors Based on Transparent Elastic Films of Carbon Nanotubes. Nat. Nanotechnol. 2011, 6 (12), 788–792.

(6)

Sun, D.; Timmermans, M. Y.; Tian, Y.; Nasibulin, A. G.; Kauppinen, E. I.; Kishimoto, S.; Mizutani, T.; Ohno, Y. Flexible High-Performance Carbon Nanotube Integrated Circuits. Nat. Nanotechnol. 2011, 6 (3), 156–161.

(7)

Cao, Q.; Kim, H.; Pimparkar, N.; Kulkarni, J. P.; Wang, C.; Shim, M.; Roy, K.; Alam, M. A.; Rogers, J. A. Medium-Scale Carbon Nanotube Thin-Film Integrated Circuits on Flexible Plastic Substrates. Nature 2008, 454 (7203), 495–500.

(8)

Xiao, L.; Chen, Z.; Feng, C.; Liu, L.; Bai, Z.-Q.; Wang, Y.; Qian, L.; Zhang, Y.; Li, Q.; Jiang, K.; Fan, S. Correction to Flexible, Stretchable, Transparent


Page 16 of 20

Page 17 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Carbon Nanotube Thin Film Loudspeakers. Nano Lett. 2012, 12 (5), 2652– 2652. (9)

Wang, C.; Hwang, D.; Yu, Z.; Takei, K.; Park, J.; Chen, T.; Ma, B.; Javey, A. User-Interactive Electronic Skin for Instantaneous Pressure Visualization. Nat. Mater. 2013, 12 (10), 899–904.

(10)

Sun, D. M.; Timmermans, M. Y.; Kaskela, A.; Nasibulin, A. G.; Kishimoto, S.; Mizutani, T.; Kauppinen, E. I.; Ohno, Y. Mouldable All-Carbon Integrated Circuits. Nat. Commun. 2013, 4, 1–8.

(11)

Wang, B.-W.; Jiang, S.; Zhu, Q.-B.; Sun, Y.; Luan, J.; Hou, P.-X.; Qiu, S.; Li, Q.-W.; Liu, C.; Sun, D.-M.; Cheng, H.-M. Continuous Fabrication of Meter-Scale Single-Wall Carbon Nanotube Films and Their Use in Flexible and Transparent Integrated Circuits. Adv. Mater. 2018, 1802057, 1802057.

(12)

Barone, P. W.; Baik, S.; Heller, D. A.; Strano, M. S. Near-Infrared Optical Sensors Based on Single-Walled Carbon Nanotubes. Nat. Mater. 2005, 4 (1), 86–92.

(13)

Yamada, T.; Hayamizu, Y.; Yamamoto, Y.; Yomogida, Y.; Izadi-Najafabadi, A.; Futaba, D. N.; Hata, K. A Stretchable Carbon Nanotube Strain Sensor for Human-Motion Detection. Nat. Nanotechnol. 2011, 6 (5), 296–301.

(14)

Takahashi, T.; Takei, K.; Gillies, A. G.; Fearing, R. S.; Javey, A. Carbon Nanotube Active-Matrix Backplanes for Conformal Electronics and Sensors. Nano Lett. 2011, 11 (12), 5408–5413.

(15)

Zhang, H.; Xiang, L.; Yang, Y.; Xiao, M.; Han, J.; Ding, L.; Zhang, Z.; Hu, Y.; Peng, L.-M. High-Performance Carbon Nanotube Complementary Electronics and Integrated Sensor Systems on Ultrathin Plastic Foil. ACS Nano 2018, 12 (3), 2773–2779.

(16)

Nela, L.; Tang, J.; Cao, Q.; Tulevski, G.; Han, S.-J. Large-Area High-Performance Flexible Pressure Sensor with Carbon Nanotube Active Matrix for Electronic Skin. Nano Lett. 2018, 18 (3), 2054–2059.

(17)

Hess, H. F.; Fulton, T. A.; Pfeiffer, L. N.; Glicofridis, P. I.; Tessmer, S. H.; Melloch, M. R.; Chang, A. M.; Glazman, L. I.; Queisser, H. J.; Hooper, W. W.;



et al. Corresponds to a Device Element with a SWNT Suspended above a Perpendicular Nanoscale. 2000, 289 (July), 5–8. (18)

Cui, J. B.; Sordan, R.; Burghard, M.; Kern, K. Carbon Nanotube Memory Devices of High Charge Storage Stability. Appl. Phys. Lett. 2002, 81 (17), 3260–3262.

(19)

Yu, W. J.; Chae, S. H.; Lee, S. Y.; Duong, D. L.; Lee, Y. H. Ultra-Transparent, Flexible Single-Walled Carbon Nanotube Non-Volatile Memory Device with an Oxygen-Decorated Graphene Electrode. Adv. Mater. 2011, 23 (16), 1889– 1893.

(20)

Javey, A.; Guo, J.; Wang, Q.; Lundstrom, M.; Dai, H. Ballistic Carbon Nanotube Field-Effect Transistors. Nature 2003, 424 (6949), 654–657.

(21)

M., E.; P., S. J.; M., S.; M., F.; A. A., G.; M. C., H.; P., A. Thin Film Nanotube Transistors Based on Self-Assembled, Aligned, Semiconducting Carbon Nanotube Arrays. ACS Nano 2008, 2 (12), 2445.

(22)

Snow, E. S.; Campbell, P. M.; Ancona, M. G.; Novak, J. P. High-Mobility Carbon-Nanotube Thin-Film Transistors on a Polymeric Substrate. Appl. Phys. Lett. 2005, 86 (3), 1–3.

(23)

Getty, S. A.; Cobas, E.; Fuhrer, M. S. Extraordinary Mobility in Semiconducting Carbon Nanotubes Extraordinary Mobility in Semiconducting Carbon Nanotubes. 2004, 4 (December 2003), 35–39.

(24)

Zou, J.; Zhang, K.; Li, J.; Zhao, Y.; Wang, Y.; Pillai, S. K. R.; Volkan Demir, H.; Sun, X.; Chan-Park, M. B.; Zhang, Q. Carbon Nanotube Driver Circuit for 6 × 6 Organic Light Emitting Diode Display. Sci. Rep. 2015, 5 (1), 11755.

(25)

Zhang, J.; Fu, Y.; Wang, C.; Chen, P.; Liu, Z.; Wei, W.; Wu, C.; Thompson, M. E.; Zhou, C. Separated Carbon Nanotube Macroelectronics for Active Matrix Organic Light-Emitting Diode Displays. Nano Lett. 2011, 11 (11), 4852–4858.

(26)

Sekitani, T.; Nakajima, H.; Maeda, H.; Fukushima, T.; Aida, T.; Hata, K.; Someya, T. Stretchable Active-Matrix Organic Light-Emitting Diode Display Using Printable Elastic Conductors. Nat. Mater. 2009, 8 (6), 494–499.


Page 18 of 20

Page 19 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(27)

Mo, Y. G.; Kim, M.; Kang, C. K.; Jeong, J. H.; Park, Y. S.; Choi, C. G.; Kim, H. D.; Kim, S. S. Amorphous-Oxide TFT Backplane for Large-Sized AMOLED TVs. J. Soc. Inf. Disp. 2011, 19 (1), 16.

(28)

Kim, H. D.; Jeong, J. K.; Chung, H.; Mo, Y. 22 . 1 : Invited Paper : Technological Challenges for Large-Size AMOLED Display Current Status and Issues on Crystallization Technology. SID Symp. Dig. Tech. Pap. 2008, 39, 291–294.

(29)

Yu, X.; Liu, D.; Kang, L.; Yang, Y.; Zhang, X.; Lv, Q.; Qiu, S.; Jin, H.; Song, Q.; Zhang, J.; Li, Q. Recycling Strategy for Fabricating Low-Cost and High-Performance Carbon Nanotube TFT Devices. ACS Appl. Mater. Interfaces 2017, 9 (18), 15719–15726.

(30)

Kim, H. D.; Chung, H.; Berkeley, B. H.; Kim, S. S. Emerging Technologies for the Commericalization of AMOLED TVs. Inf. Disp. (1975). 2009, 9, 18–22.

(31)

Kwon, J. Y.; Son, K. S.; Jung, J. S.; Kim, T. S.; Ryu, M. K.; Park, K. B.; Yoo, B. W.; Kim, J. W.; Lee, Y. G.; Park, K. C.; Lee, S. Y.; Kim, J. M. Bottom-Gate Gallium Indium Zinc Oxide Thin-Film Transistor Array for High-Resolution AMOLED Display. IEEE Electron Device Lett. 2008, 29 (12), 1309–1311.

(32)

Lau, P. H.; Takei, K.; Wang, C.; Ju, Y.; Kim, J.; Yu, Z.; Takahashi, T.; Cho, G.; Javey, A. Fully Printed, High Performance Carbon Nanotube Thin-Film Transistors on Flexible Substrates. Nano Lett. 2013, 13 (8), 3864–3869.

(33)

Ha, T.-J.; Chen, K.; Chuang, S.; Yu, K. M.; Kiriya, D.; Javey, A. Highly Uniform and Stable N-Type Carbon Nanotube Transistors by Using Positively Charged Silicon Nitride Thin Films. Nano Lett. 2015, 15 (1), 392–397.



TOC:

A flexible 64 × 64 pixel active matrix light-emitting diode display driven by CNT thin-film transistors, that has uniform brightness and a high yield of 99.93% in its 4096 pixels. More than 8000 thin-film transistors with high-purity semiconducting CNTs as the channel material show an average on-off current ratio of ~107, a carrier mobility of 16 cm2V−1s−1, the driving circuit can still maintain normal operation under the condition that the bending strain reaches 0.4%.


Page 20 of 20

Flexible 64 Ã 64 Pixel AMOLED Displays Driven by Uniform Carbon

Recommend Documents

Flexible 64 Ã 64 Pixel AMOLED Displays Driven by Uniform Carbon