Ultra-Smooth QDs Micro-Patterns by a Facile Controllable Liquid

Subscriber access provided by UNIVERSITY OF TOLEDO LIBRARIES

Article

Ultra-Smooth QDs Micro-Patterns by a Facile Controllable Liquid Transfer Approach: Low-Cost Fabrication of High-Performance QLED Min Zhang, Binbin Hu, Lili Meng, Ruixin Bian, Siyuan Wang, Yunjun Wang, Huan Liu, and Lei Jiang J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.8b02948 • Publication Date (Web): 12 Jun 2018 Downloaded from http://pubs.acs.org on June 12, 2018

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 7 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

Journal of the American Chemical Society

Ultra-Smooth QDs Micro-Patterns by a Facile Controllable Liquid Transfer Approach: Low-Cost Fabrication of High-Performance QLED Min Zhang,†, ‡,# Binbin Hu,‡,# Lili Meng,† Ruixin Bian,† Siyuan Wang,§ Yunjun Wang,§ Huan Liu†,* and Lei Jiang† †

Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing, 100191, P. R. China ‡ Key Lab for Special Functional Materials of Ministry of Education, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng, 475000, P. R. China § Suzhou Xingshuo Nanotech Co., Ltd (Mesolight), Suzhou, 215123, P. R. China # These two authors contribute equally Keywords: fibers, liquid transfer, ultra-smooth micro-patterns, QLED, low-cost

* Supporting Information ABSTRACT: Fabrication of a high quality quantum dots (QDs) film is essentially important for a high-performance QDs light emitting diode display (QLED) device. It is normally a high-cost and multiple-step solution transfer process where large amount of QDs was needed but with only limited useful. Thus, developing a simple, efficient and low-cost approach to fabricate high quality micro-patterned QDs film is urgently needed. Here, we proposed that the Chinese brush enables the controllable transfer of QDs solution directly into homogeneous and ultra-smooth micro-patterned film in one-step. It is proposed that the dynamic balance of QDs was enables during the whole solution transfer process, under the cooperative effect of Marangoni flow aroused by the asymmetric solvent evaporation and the Laplace pressure different by conical fibers. By this approach, QDs nanoparticles were homogeneously transferred onto the desired area on the substrate. The as-prepared QLED devices show rather high performances with the current efficiency of 72.38, 26.03 and 4.26 cd/A, and external quantum efficiency of 17.40, 18.96 and 6.20 % for the green, red and blue QLED devices, respectively. We envision the result offers a low-cost, facile and practical applicable solutionprocessing approach that works even in the air, for fabricating high performance QLED devices.

1. INTRODUCTION Quantum dots light emitting diode (QLED) display, as the most promising next generation LED display, have attracted a lot of attentions due to its stable optical performance, narrow spectral emission bandwidths, and high screen resolution.1-7 As the emitting layer, the quantum dots (QDs) film plays an important role to determine the performance of QLED devices.8-11 Generally, the performance of the QDs film depends on both the physicochemical property of QDs themselves and the quality of the assembled film, particularly the uniformity and the thickness.12-17 QDs film with suitable thickness is always preferred for the efficient charge transfer across the film.18 Particularly, the surface roughness of the QDs film affects both its charge transport behavior and the charge balance with the neighboring layer in the multilayered device, which affects the quantum efficiency directly. Meanwhile, considering the high cost of QDs, it is in demand to pattern QDs film in the functional area. Therefore, it is rather important to prepare high quality micro-patterned QDs films from the viewpoint of practical applications. So far, various solution-processes have been developed for preparing QDs films including spin-coating,19-23 transfer printing,10, 18, 2427 ink-jet printing28-30 and mist-deposition31. However, these techniques suffer from limitations as high-cost, complicated

multiple-steps, demands for template, shortage in film uniformity. For example, the spin-coating and the mistdeposition normally need large amount of QDs solution but with only very limited amount actually transferred, which make it a high-cost process. The transfer printing requires templates, making process more complicated. The ink-jet printing suffer from both the coffee ring effect and easy-clog of the jagged nozzle. Thus, developing a simple and low-cost solution-processing approach that can directly fabricate uniform QDs film with various micro-patterns is rather important for high-performance QLED, which remains challenge. Here, drawn inspirations from the controllable liquid transfer by the Chinese brush,32-35 we develop a facile brushcoating approach to transfer QDs solution directly into ultrasmooth micro-patterns in a controllable manner, by which high performance QLED devices were fabricated with rather low-cost. It is proposed that the brush-coating enables the dynamic balance of QDs during the whole solution transfer process, under the cooperative effect of the Marangoni flow of QDs in the liquid aroused by the asymmetric solvent evaporation and the Laplace pressure different by conical structure. By this approach, QDs solution was homogeneously transferred onto the desired area on the substrate without any uncontrollable aggregations, leading to an ultra-smooth micro-

1 Environment ACS Paragon Plus

Journal of the American Chemical Society 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

patterned QDs film. Thus, QLED devices with rather high performances were achieved, exhibiting the peak current efficiency of 72.38, 26.03 and 4.26 cd/A, and peak external quantum efficiency (EQE) of 17.40, 18.96 and 6.20 % for green, red and blue QLEDs, respectively. Worthnoting is that here the QDs films were prepared by brushing in air condition, which is important for large-mass production. We envision that the result offers an alternate simple approach for the lowcost fabrication of high-performance QLED-devices.

2. RESULTS AND DISCUSSION For a QLED device with typical multiple-layered structure, the emitting layer of QDs film is crucial (Figure 1a), which generally derives from QDs solution. By brush-coating, the QDs solution is steadily transferred onto the micro-scale functional area on the substrate in a well-controllable manner, as schematically shown in Figure 1b. The most advantage of the brush-coating over other solution processes is that it enables direct preparing micro-patterned QDs film with rather high uniformity free from any templates, as shown in Figure 1c. As can be seen from the photoluminescence images under the UV irradiation, all the green, red and blue QDs films with a width of ca. 500 µm show good homogeneous throughout the whole film (Figure 1d, 1e, 1f). Moreover, the as-prepared QDs films show well-defined profile without any coffee ring or ripples. Nanoparticles in the film are distributed uniformly to form homogeneous color emitting light. Here, the ligand of octylamine, n-octylmercaptan and octylamine were particularly used for green, red and blue QDs, respectively (Figure S1), which show little effect on the film formation in our system. It is rather reasonable that these ligands are all oleophilic, showing similar effect on the interactions among ligands on neighboring QDs and the substrate. When the QDs films were integrated into the QLED devices with four functional regions, the uniformly luminous were obtained for all green, red and blue QLEDs without any observable difference in luminous intensity (Figure 1g, 1h, and 1i). To be noticed, only small amount of QDs solution was needed for the brush-coating, which suggested a low-cost process. Taken together, the brush-coating enables controllable transfer of QDs solution into micro-patterns with high uniformity free from any templates, which is advantage for low-cost fabrication of QLEDs.

Figure 1. Direct preparing micro-patterned QDs film by the Chinese brush. (a) QLED device with a typical multiple-layered stucture. (b) Schematic illustrations of brush-coating process, and the typical CdZnSeS@ZnS core/shell structure of QDs nanoparticles. Inset: n-octane and water droplets spread on the TFB layer. (c) Micro-patterned green QDs film by brush-coating method, where the QDs was only deposited onto specified functional areas. (d, e and f) Fluorescence microscope images of the as-brushed green, red and blue QDs film under UV irradiation. (g, h and i) Electroluminescent images of the Green-, Red- and Blue-QLED devices.

The uniformity and roughness of QDs films were further characterized by the magnified photoluminescence (PL) microscope and the Atomic Force Microscope (AFM), respectively. As shown in Figure 2a - 2c, the brush-coated QDs films exhibit rather good homogeneous distribution within all the area, showing well defined profile. For comparison, the spin-coated QDs films are unable to give any clear profile, despite its certain uniformity (Figure 2d). As have been measured by AFM, the roughness of the brushcoated QDs film is as small as ca. 1.10 nm (Figure 2e), which is much smaller than that of the spin-coated one (Rms = 2.84 nm, Figure 2f). The film thickness is measured as ca. 8 nm for the brush-coated QDs film (Figure S2). Here, the brushcoating show advantages not only in preparing micropatterned QDs film, but also enables the ultra-smooth QDs film, which are beneficial for the high performance of QLED.36-37

Figure 2. The PL and AFM characterization of as-prepared QDs film. Fluorescence microscope images of green (a1, a2), red (b1, b2), and blue (c1, c2) QDs films prepared by the brush-coating, and by the spin-coating (d1, d2 and d3). Among them, (a1, b1 and c1) show the inner region of QDs films; (a2, b2 and c2) show distinct boundary of the QDs films; (d1, d2 and d3) show the QDs films by spin-coating where no clear boundary was observed (the scale bar is 10 µm). (e, f) The representative AFM height image


Page 2 of 7

Page 3 of 7 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

Journal of the American Chemical Society and the three-dimensional image show Rms of 1.10 nm for brushcoated QDs films, and Rms of 2.84 nm for spin-coated QDs films.

To explore the performance of the brush-coated QDs films, the QLED devices with the architecture of glass/ITO/ poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) /poly[9,9-dioctylfluorene-co-N-[4-(3methylpropyl)]-dipheny-lamine] (TFB)/CdZnSeS@ZnScoreshell QDs/Zinc oxide(ZnO) /Al cathode are fabricated (Figure 1a). Here, the TFB polymer layer acts as the hole transport layer, and the ZnO layer acts as the electron transport layer. The CdZnSeS@ZnS QDs film, which is fabricated by the brush coating, acts as the emission layer that is inserted between the hole transport layer and the electron transport layer.38-40 As summarized in Figure 3, the as-prepared QLED devices show rather good electroluminescent performances. The symmetric emission peak for the brush-coated QDs films at 528, 624 and 468 nm give a narrow full width at half maximum (FWHM) of 23, 28 and 20 nm for the green, red and blue QLED devices (Figure 3a1, 3b1 and 3c1) respectively. The FWHM of emission spectra and the EL peak position remain unchanged with increasing the driving voltage. This is rather important for practical applications since it suggests the high stability of the EL emission for the QLED devices. For a green-QLED, the current density and luminance show clear increase with enlarging the voltage (Figure 3a2), yielding a maximum luminance of over 12000 cd/m2 at 4.4 V. Here, the maximum current efficiency of 72.38 cd/A and the current density of 4.99 mA/cm2 was achieved for the green-QLED. This current efficiency value exceeds most reported QLED devices in literatures.1-4, 10, 22, 24-25, 28-29, 41-43 Moreover, the current efficiency is more than 60 cd/A in a wide current density range (Figure 3a3). The peak EQE of the green-QLED is as large as 17.40 %, which can be maintained at greater than 15 % at current densities in the range of 0.6 - 20 mA/cm2, corresponding to a luminance in the range of 379 - 12000 cd/m2 (Figure 3a2 and 3a3). For red- (Figure 3b2, 3b3) and blue- (Figure 3c2, 3c3) QLED devices, the maximum luminance of 4500 cd/m2 at 4 V and 315 cd/m2 at 5 V, the maximum current efficiency of 26.03 and 4.26 cd/A, and the peak EQE of 18.96 % and 6.20 % were realized, respectively. Thus, the brush-coated QLEDs devices give rather good performances, better than that of spin-coated QLED devices (Figure S3-S4) under the same experimental condition, which represent a rather high performance for most recently reported QLED devices with similar structure fabricated by other solution processes (Figure S5). It thus offer a facile, low-cost, yet applicable approach for the practical applications of QLEDs.

Figure 3. The performance of green-, red- and blue- QLED devices. (a1, b1 and c1) EL spectral evolutions of three colored QLED devices with increasing driving voltage. (a2, b2 and c2) Current density and luminance characteristics of the driving voltage with the best efficiency in the green-, red- and blueQLED devices. (a3, b3 and c3) Current efficiency and EQE characteristics of the current density with the best efficiency in these QLED devices.

Conical fibers with quasi-parallel configuration are the essence for the controllable liquid transfer of the Chinese brush,44-46 which responsible for the homogeneous QDs film under the operation condition. As schematically shown in Figure 4, the ultra-smooth QDs film is attributable to the controllable wetting and dewetting guided by the conical fibers, 47 where the dynamic balance of QDs in the solution was maintained without any unexpected aggregation during the whole transfer process. Particularly, the solvent of noctane with rather low surface tension of 21.8×10-3 N/m was used in our case, which is liable to spread and difficult to control (Figure 1b, Figure S6). Here, we demonstrated that both polar (toluene) and nonpolar (n-octane) solvent can be used to realize the high quality QDs films (Figrue S7), suggesting the little effect of the solvent polarity on the film formation. When the Chinese brush moves at a certain speed V, large mass of QDs solution was steadily held within the brush as the cooperative effect of Laplace pressure difference FL, asymmetrical retention force Fa and gravity G (Figure 4a, area 1),48-51 leaving the front edge of the solution film under the directional stress of FL via each single fiber and the surface tension (Fɣ) at each neighboring fibers (Figure 4a, area 2). Here, the liquid-gas-solid three phase contact line (TCL) was shaped into multiple small meniscus curves by parallel conical fibers, where multiple parallel Fɣ were generated to guide the solution transfer (Figure 4c). To be noticed, the most advantage of the Chinese brush in transferring QDs solution lies in that the FL via each single fiber can help to propel the QDs moving to the base side of fibers, which can be used to counter the Marangoni flow of QDs in the solution aroused by the asymmetric solvent evaporation,52-56 as indicated in Figure 4b. As a cooperative effect of these two driving forces with opposite directions, the dynamic balance of QDs in the solution was enabled during the whole transfer process, leading to a homogeneous QDs film. For the QLED display, the film uniformity is necessary not only for large scale QDs film, but for micro-scale patterns of each RGB three-colors unit.12 Here, not limited to the micro-scale, the brush-coating enables a highly uniformed QDs film in a large scale, as has been demonstrated by a uniform QDs film with a width of ca. 1 cm and a length of ca. 6 cm (Figure 4d).



using brushing speed of 3 mm/s at room temperature (ca. 25oC). Taken together, the self-assmbly of QDs with finecontrolled duration time was enabled under certain driving force, which makes the liquid transfer to be quasi-steady throughout the whole process. As a result, the high quality QDs films are realized.

Figure 4. Schematic cartoons of the dynamic balance of QDs during the whole solution transfer process guided by the Chinese brush. (a) The side-view cartoon of the brush coating process, where the transfer of the QDs solution was finely tuned under the direction stress aroused by conical fibers. In area 1, the QDs solution was steadily held within the brush as the cooperative effect of FL, Fa and G. (b) In area 2, the fibers propel the QDs moving to the base side of fibers under the FL and Fɣ, which be used to balance the Marangoni flow of QDs solution aroused by the asymmetric solvent evaporation. σ is surface tension. (c) The top-view cartoon of the TCLs guided by the conical fibers, showing multiple meniscus-shaped TCLs within two neighboring fibers, which helps generating the direction stress along the fibers. (d) The optical picture of brushing process where the QDs solution was homogenously transferred onto the substrate with a clear boundary.

Here, the brushing speed (i.e. the moving speed of brush vs. the substrate) of 3 mm/s delivers the high quality ultra-smooth QDs film. In our case, the brushing speed is a crucial parameter to realize the controllable transfer of QDs solution, which makes the spreading and dewetting of solution matches with each other. That is to say, the brushing speed directly affects the receding pattern of TCL, the duration time for nanoparticles assembly, and the movement and distribution of QDs nanoparticles in solution. Here, the QDs film prepared with different brushing speed was characterized by AFM (Figure S8). It is clearly that different brushing speed gave drastically different morphologies of QDs films. When the speed is too slow, the dewetting of solution on the substrate is much faster than the spreading of the solution, which makes the movement of QDs nanoparticles in solution hard to proceed. As a result, the nanoparticles fail to be uniformly transferred onto the substrate (Figure S8a - S8c). When the speed is too fast, the dewetting of solution on the substrate is slower than its spreading, which lead to a long duration time for the QDs self-assembly. In this situation, the self-assembly of QDs liable to be proceed randomly, leading to a rough QDs film (Figure S8d - S8h). Suitable brushing speed enables the balance of the wetting and dewetting of QDs solution on the substrate, where the liquid front edge is the TCL governed by conical fibers. Another parameter affecting the spreading and dewetting of QDs solution on the substrate is the temperature, increasing which can largely accelerate the dewetting process. As a result, the balance of the wetting and dewetting of QDs solution on the substrate was broken, leading to the aggregating of QDs within the film (Figure S9), which is not favored for high performance QLED devices. Here, the best condition for yielding high qulity QDs film in our system is

Figure 5. Various QDs micro-patterns were prepared directly by brushing-coating free from any templates. By adjusting the brushing conditions, micro-patterned QDs films with good uniformity were obtained. Various green QDs micro-lines arrays with stripes width increases from (a, b and c) 40, 80 to 180 µm, and (d, e, and f) 60, 100 to 190 µm were prepared. (g, h, i and j) Some curved QDs micro-patterns were prepared by brushcoating, such as (g) a triangle, (h) a square, (i) a semicircle, and (j) a wavy.

Moreover, the Chinese brush enabled various micropatterned QDs films free from any templates. By fixing the brush on a programmable three-axis (x-y-z) motion stage, both the brushing speed and the direction/moving trace can be accurately controlled by a software (Figure S10). Thus, varies patterns can be directly brushed on the substrate using QDs solution. As shown in Figure 5, arrays of QDs micro-lines with different width and space were prepared. Figure 5a - 5c show the QDs micro-lines with the width increasing from the 40, 80 to 180 µm. Figure 5d - 5f show the QDs micro-lines with the width increasing from 60, 100 to 190 µm. Meanwhile, various curved micro-patterns were also enabled by brushcoating as a triangle, a square, a semicircle, a wavy (Figure 5g - 5j). The well-defined profile and homogeneous uniform fluorescent colors of these patterns were confirmed, which offer a solution for preparing various complex patterns by the Chinese brush.

3. CONCLUSIONS In this contribution, we present a simple yet efficient approach of Chinese brush-coating to prepare ultra-smooth QDs micro-patterns by using a small amount of QDs solution in one-step. Under the cooperative effect of the Marangoni flow of QDs solution and the Laplace pressure aroused by conical fibers, QDs solution was controllably transferred onto the desired area on the substrate homogeneously with rathersmall roughness. The resulting green-, red- and blue-QLED devices gave high performances with the peak current efficiency of 72.38, 26.03 and 4.26 cd/A, and the peak EQE of 17.40, 18.96 and 6.20%, respectively. Different from other solution processing approaches, the brush-coating enables fabricating ultra-smooth QDs films with various micro-


Page 4 of 7

Page 5 of 7 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

Journal of the American Chemical Society patterns without any template. Therefore, we envision it would provides a new template-free, low-cost and facile solutionprocessing approach in fabricating high-performance QLED devices.

4. EXPERIMENTAL SECTION Materials. All brush used in our experiment were purchased from Beijing Jinghua Brush Co., Ltd and Yuanwang painting materials. QDs solutions were kindly provided by Suzhou Xingshuo Nanotech Co., Ltd. n-Octane, acetone and isopropanol were purchased from Beijing Chemical Works and used as received. The mico-patterned QDs film preparation by the Chinese brush. The Chinese brush was cleaned by ultra-sonication in deionized water and ethanol for 10 min, and then dried using an N2 stream. The substrates were cleaned consecutively in ultrasonic baths of deionized water, acetone and isopropanol for 15 min each, and then dried using an N2 stream. By the brushcoating, the QDs solution was transferred onto the substrate homogeneously and also in a well controllable manner. Here, the moving behaviors of the Chinese brush (speed, direction) weres accurately controlled by a programmable three-axis (x-y-z) motion stage by using software; while the interaction between the brush and the substrate was fixed as a certain value of H. Substrate temperature is controlled by a hot plate. Spin-coated QDs films were fabricated at 2000 r. p. m. for 40 s. Concentration of green, red and blue quantum dots were 13 mg/ml, 17 mg/ml and 10 mg/ml, respectively. For QDs micro-line arrays, changing the number of fibers lead to the micro-lines with different width. All experiments were performed at room temperature. Devices preparation. Patterned ITO glass pre-coated with TFB and PEDOT:PSS was prepared according to the literature under vacuum condition. Red, green and blue-emissive QDs films were brush-coated on the top of the TFB layer. Finally, the multilayer samples were loaded into a high-vacuum chamber for spin-coating ZnO as an electron transport layer, followed by the deposition of an Al cathode. We characterized the voltage-current density/luminance, current density-current efficiency/ EQE, and electroluminescence spectral performance of red, green and blue devices using Spectrascan PR655. Characterization of the Microstructures. The optical images of the QDs patterns were recorded by a digital video camera (Nikon, N1406 D7200). Photoluminescence (PL) images were taken by fluorescence microscope (OLYMPUS, BX53). The micro-structures of the QDs film were observed by an atomic force microscope (FASTSCANBIO, Bruker, Germany). The performance of QLED devices was characterized with the assist of Suzhou Xingshuo Nanotech Co., Ltd.

ASSOCIATED CONTENT Supporting Information The Supporting Information is available free of charge on the ACS Publications website. Experimental details, methods and additional data. (Figures S1S10) (PDF)

AUTHOR INFORMATION Corresponding Author *[email protected]

ORCID HuanLiu：0000-0001-9009-7122

All authors have given approval to the final version of the manuscript. The authors declare no competing financial interest.

ACKNOWLEDGMENT This work was financially supported by the National Natural Science Foundation of China (21622302, 21574005), and the Fundamental Research Funds for the Central Universities. We greatly thank for the Suzhou Xingshuo Nanotech Co., Ltd for the helpful assist in the experiment.

REFERENCES (1) Dai, X.; Zhang, Z.; Jin, Y.; Niu, Y.; Cao, H.; Liang, X.; Chen, L.; Wang, J.; Peng, X. Nature 2014, 515 (7525), 96-99. (2) Kim, B. H.; Nam, S.; Oh, N.; Cho, S. Y.; Yu, K. J.; Lee, C. H.; Zhang, J.; Deshpande, K.; Trefonas, P.; Kim, J. H.; Lee, J.; Shin, J. H.; Yu, Y.; Lim, J. B.; Won, S. M.; Cho, Y. K.; Kim, N. H.; Seo, K. J.; Lee, H.; Kim, T. I.; Shim, M.; Rogers, J. A. ACS Nano 2016, 10 (5), 4920-4925. (3) Kim, B. H.; Onses, M. S.; Lim, J. B.; Nam, S.; Oh, N.; Kim, H.; Yu, K. J.; Lee, J. W.; Kim, J. H.; Kang, S. K.; Lee, C. H.; Lee, J.; Shin, J. H.; Kim, N. H.; Leal, C.; Shim, M.; Rogers, J. A. Nano Lett. 2015, 15 (2), 969-973. (4) Lee, K.-H.; Han, C.-Y.; Kang, H.-D.; Ko, H.; Lee, C.; Lee, J.; Myoung, N.; Yim, S.-Y.; Yang, H. ACS Nano 2015, 9, 10941–10949. (5) Lin, Q.; Song, B.; Wang, H.; Zhang, F.; Chen, F.; Wang, L.; Li, L. S.; Guo, F.; Shen, H. J. Mater. Chem. C 2016, 4 (30), 7223-7229. (6) Shirasaki, Y.; Supran, G. J.; Bawendi, M. G.; Bulović, V. Nature Photon. 2012, 7 (1), 13-23. (7) Wong, A. B.; Lai, M.; Eaton, S. W.; Yu, Y.; Lin, E.; Dou, L.; Fu, A.; Yang, P. Nano Lett. 2015, 15 (8), 5519-5524. (8) Cho, Y. R.; Kang, P.-G.; Shin, D. H.; Kim, J.-H.; Maeng, M.-J.; Sakong, J.; Hong, J.-A.; Park, Y.; Suh, M. C. Appl. Phys. Express 2016, 9 (1), 012103. (9) Kim, H. M.; Geng, D.; Kim, J.; Hwang, E.; Jang, J. ACS Appl. Mater. Interfaces 2016, 8, 28727-28736. (10) Choi, M. K.; Yang, J.; Kang, K.; Kim, D. C.; Choi, C.; Park, C.; Kim, S. J.; Chae, S. I.; Kim, T. H.; Kim, J. H.; Hyeon, T.; Kim, D. H. Nat. Commun. 2015, 6, 7149. (11) Mashford, B. S.; Stevenson, M.; Popovic, Z.; Hamilton, C.; Zhou, Z.; Breen, C.; Steckel, J.; Bulovic, V.; Bawendi, M.; CoeSullivan, S.; Kazlas, P. T. Nature Photon. 2013, 7 (5), 407-412. (12) Dai, X.; Deng, Y.; Peng, X.; Jin, Y. Adv. Mater. 2017, 29 (14), 1607022. (13) Pan, J.; Chen, J.; Zhao, D.; Huang, Q.; Khan, Q.; Liu, X.; Tao, Z.; Zhang, Z.; Lei, W. Opt. Express 2016, 24 (2), A33-A43. (14) Wang, X.; Li, W.; Sun, K. J. Mater. Chem. 2011, 21, 8558– 8565. (15) Zhang, H.; Sui, N.; Chi, X.; Wang, Y.; Liu, Q.; Zhang, H.; Ji, W. ACS Appl. Mater. Interfaces 2016, 8 (45), 31385-31391. (16) Shen, H.; Bai, X.; Wang, A. Q.; Wang, H.; Qian, L.; Yang, Y.; Titov, A.; Hyvonen, J.; Zheng, Y.; Li, L. S. Adv. Funct. Mater. 2014, 24 (16), 2367-2373. (17) Dou, L.; Lai, M.; Kley, C. S.; Yang, Y.; Bischak, C. G.; Zhang, D.; Eaton, S. W.; Ginsberg, N. S.; Yang, P. Proc. Natl. Acad. Sci. U S A 2017, 114 (28), 7216-7221. (18) Kim, T.-H.; Cho, K.-S.; Lee, E. K.; Lee, S. J.; Chae, J.; Kim, J. W.; Kim, D. H.; Kwon, J.-Y.; Amaratunga, G.; Lee, S. Y.; Choi, B. L.; Kuk, Y.; Kim, J. M.; Kim, K. Nature Photon. 2011, 5 (3), 176182. (19) Kwak, J.; Bae, W. K.; Lee, D.; Park, I.; Lim, J.; Park, M.; Cho, H.; Woo, H.; Yoon, D. Y.; Char, K.; Lee, S.; Lee, C. Nano Lett. 2012, 12, 2362-2366. (20) Lee, K.-H.; Han, C.-Y.; Kang, H.-D.; Ko, H.; Lee, C.; Lee, J.; Myoung, N.; Yim, S.-Y.; Yang, H. ACS Nano 2015, 9 (11), 10941– 10949. (21) Cho, K.-S.; Lee, E. K.; Joo, W.-J.; Jang, E.; Kim, T.-H.; Lee, S. J.; Kwon, S.-J.; Han, J. Y.; Kim, B.-K.; Choi, B. L.; Kim, J. M. Nature Photon. 2009, 3 (6), 341-345.

Author Contributions



(22) Yang, Y.; Zheng, Y.; Cao, W.; Titov, A.; Hyvonen, J.; Manders, J. R.; Xue, J.; Holloway, P. H.; Qian, L. Nature Photon. 2015, 9, 259–266. (23) Jiang, P.; McFarland, M. J. J. Am. Chem. Soc. 2004, 126, 13778-13786. (24) Cho, H.; Kwak, J.; Lim, J.; Park, M.; Lee, D.; Bae, W. K.; Kim, Y. S.; Char, K.; Lee, S.; Lee, C. ACS Appl. Mater. Interfaces 2015, 7 (20), 10828-10833. (25) Li, J.; Xu, L.; Tang, C. W.; Shestopalov, A. A. ACS Appl. Mater. Interfaces 2016, 8 (26), 16809-16815. (26) Yan, X.; Yao, J.; Lu, G.; Chen, X.; Zhang, K.; Yang, B. J. Am. Chem. Soc. 2004, 126, 10510-10511. (27) Bhandari, D.; Kravchenko, II; Lavrik, N. V.; Sepaniak, M. J. J. Am. Chem. Soc. 2011, 133 (20), 7722-7724. (28) Jiang, C.; Zhong, Z.; Liu, B.; He, Z.; Zou, J.; Wang, L.; Wang, J.; Peng, J.; Cao, Y. ACS Appl. Mater. Interfaces 2016, 8 (39), 2616226168. (29) Zhang, L.; Liu, H.; Zhao, Y.; Sun, X.; Wen, Y.; Guo, Y.; Gao, X.; Di, C. A.; Yu, G.; Liu, Y. Adv. Mater. 2012, 24 (3), 436-440. (30) Parry, A. V.; Straub, A. J.; Villar-Alvarez, E. M.; Phuengphol, T.; Nicoll, J. E.; W, K. X.; Jordan, L. M.; Moore, K. L.; Taboada, P.; Yeates, S. G.; Edmondson, S. J. Am. Chem. Soc. 2016, 138 (29), 9009-9012. (31) Zhu, T.; Shanmugasundaram, K.; Price, S. C.; Ruzyllo, J.; Zhang, F.; Xu, J.; Mohney, S. E.; Zhang, Q.; Wang, A. Y. Appl. Phys. Lett. 2008, 92 (2), 023111. (32) Wang, Q.; Meng, Q.; Liu, H.; Jiang, L. Nano Res. 2015, 8 (1), 97-105. (33) Wang, G.; Huang, W.; Eastham, N. D.; Fabiano, S.; Manley, E. F.; Zeng, L.; Wang, B.; Zhang, X.; Chen, Z.; Li, R.; Chang, R. P. H.; Chen, L. X.; Bedzyk, M. J.; Melkonyan, F. S.; Facchetti, A.; Marks, T. J. Proc. Natl. Acad. Sci. U S A 2017, 114 (47), E10066-E10073. (34) Cai , Y.; Newby, B. Z. J. Am. Chem. Soc. 2008, 130, 6076– 6077. (35) Yella, A.; Tahir, M. N.; Meuer, S.; Zentel, R.; Berger, R.; Pantho¨fer, M.; Tremel, W. J. Am. Chem. Soc. 2009, 131, 17566– 17575. (36) Shen, H.; Cao, W.; Shewmon, N. T.; Yang, C.; Li, L. S.; Xue, J. Nano Lett. 2015, 15 (2), 1211-1216. (37) Anikeeva, P. O.; Halpert, J. E.; Bawendi, M. G.; Bulovic´, V. Nano Lett. 2009, 9, 2532-2536.

(38) Kim, J. H.; Lee, K. H.; Kang, H. D.; Park, B.; Hwang, J. Y.; Jang, H. S.; Do, Y. R.; Yang, H. Nanoscale 2015, 7 (12), 5363-5370. (39) Liang, H.; Luo, Z.; Zhu, R.; Dong, Y.; Lee, J.-H.; Zhou, J.; Wu, S.-T. J. Phys. D: Appl. Phys. 2016, 49 (14), 145103. (40) Shen, H.; Lin, Q.; Wang, H.; Qian, L.; Yang, Y.; Titov, A.; Hyvonen, J.; Zheng, Y.; Li, L. S. ACS Appl. Mater. Interfaces 2013, 5 (22), 12011-12016. (41) Cao, F.; Wang, H.; Shen, P.; Li, X.; Zheng, Y.; Shang, Y.; Zhang, J.; Ning, Z.; Yang, X. Adv. Funct. Mater. 2017, 27 (42), 1704278. (42) Park, J. S.; Kyhm, J.; Kim, H. H.; Jeong, S.; Kang, J.; Lee, S. E.; Lee, K. T.; Park, K.; Barange, N.; Han, J.; Song, J. D.; Choi, W. K.; Han, I. K. Nano Lett. 2016, 16 (11), 6946-6953. (43) Zheng, H.; Zheng, Y.; Liu, N.; Ai, N.; Wang, Q.; Wu, S.; Zhou, J.; Hu, D.; Yu, S.; Han, S.; Xu, W.; Luo, C.; Meng, Y.; Jiang, Z.; Chen, Y.; Li, D.; Huang, F.; Wang, J.; Peng, J.; Cao, Y. Nat. Commun. 2013, 4, 1971. (44) Yamamoto, T.; Meng, Q.; Liu, H.; Jiang, L.; Doi, M. Langmuir 2016, 32 (13), 3262-3268. (45) Wang, Q.; Su, B.; Liu, H.; Jiang, L. Adv. Mater. 2014, 26 (28), 4889-4894. (46) Kim, H. S.; Lee, C. H.; Sudeep, P. K.; Emrick, T.; Crosby, A. J. Adv. Mater. 2010, 22 (41), 4600-4604. (47) Huang, J.; Kim, F.; Tao, A. R.; Connor, S.; Yang, P., Nat. Mater. 2005, 4 (12), 896-900. (48) Duprat, C.; Protière, S.; Beebe, A. Y.; Stone, H. A., Nature 2012, 482 (7386), 510-513. (49) Lin, F.-J.; Guo, C.; Chuang, W.-T.; Wang, C.-L.; Wang, Q.; Liu, H.; Hsu, C.-S.; Jiang, L. Adv. Mater. 2017, 1606987. (50) Yamamoto, T.; Meng, Q. a.; Wang, Q.; Liu, H.; Jiang, L.; Doi, M. NPG Asia Mater. 2016, 8 (2), e241. (51) Lodge, R. A.; Bhushan, B. J. Appl. Polym. Sci. 2006, 102 (6), 5255-5265. (52) Deegan, R. D.; Bakajin, O.; Dupont, T. F.; Huber, G.; Nagel, S. R.; Witten, T. A. Nature 1997, 389 (6653), 827-829. (53) Hu, H.; Larson, R. G. J. Phys. Chem. B 2006, 110, 7090-7094. (54) Karpitschka, S.; Liebig, F.; Riegler, H. Langmuir 2017, 33 (19), 4682-4687. (55) Tsoumpas, Y.; Dehaeck, S.; Rednikov, A.; Colinet, P. Langmuir 2015, 31 (49), 13334-13340. (56) Zhang, Z.; Peng, B.; Ji, X.; Pei, K.; Chan, P. K. L. Adv. Funct. Mater. 2017, 1703443.


Page 6 of 7

Page 7 of 7 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

Journal of the American Chemical Society

Artwork for TOC Ultra-Smooth QDs Micro-Patterns by a Facile Controllable Liquid Transfer Approach: Low-Cost Fabrication of HighPerformance QLED

ACS Paragon Plus Environment

Ultra-Smooth QDs Micro-Patterns by a Facile Controllable Liquid

Recommend Documents