One-Step Synthesis of FA-Directing FAPbBr3 Perovskite Nanocrystals

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Functional Nanostructured Materials (including low-D carbon)

One-step synthesis of FA-directing FAPbBr3 perovskite nanocrystals towards high performance display Yu-Long Tong, Ya-Wen Zhang, Kangzhe Ma, Rui Cheng, Fengxiang Wang, and Su Chen ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.8b10366 • Publication Date (Web): 28 Aug 2018 Downloaded from http://pubs.acs.org on August 28, 2018

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ACS Applied Materials & Interfaces

One-step

synthesis

of

FA-directing

FAPbBr3

perovskite nanocrystals towards high performance display Yu-Long Tong, Ya-Wen Zhang, Kangzhe Ma, Rui Cheng, Fengxiang Wang and Su Chen* State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials, Nanjing Tech University, 5 Xin Mofan Road, Nanjing 210009, P. R. China. KEYWORDS perovskite nanocrystals, anion-exchange reaction, white light-emitting diode, display backlight, inkjet printing

ABSTRACT: Hybrid organic-inorganic and all-inorganic metal halide perovskite nanocrystals (PNCs) have aroused extensive attention from both academic and industrial researchers considering their excellent performance in optoelectronic applications. Herein, we develop a facile and time-saving strategy to synthesize NH2CH=NH2PbBr3 (NH2CH=NH+, FA) PNCs at room temperature. Benefiting from this facile method, high quality FAPbBr3 PNCs with photoluminescence quantum yield (PLQY) up to 76% and narrow full-width at half-maxima (FWHM) of 20 nm can be produced on a large scale. Moreover, anion-exchange reactions run by using FAPbBr3 as template, producing various PNCs with different anion constituents. By

ACS Paragon Plus Environment

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manipulating the ratios of two different anions, a series PNCs with various bright photoluminescence ranging from 452 nm to 646 nm could be done. On account of superior and adjustable photoluminescence over the visible spectral region, FAPbBr3 PNCs can be applied as a promising color-converting material in liquid crystal display (LCD) backlight, white lightemitting diode (WLED) and inkjet printing pattern. As proof of concept, FAPbBr3 PNCs with green emission were integrated in WLED and LCD backlight, accomplishing a color rendering index of 87.5 and a wide color gamut of 116%, respectively.

INTRODUCTION Perovskite nanocrystals (PNCs) including all-inorganic CsPbBr3 and organic-inorganic MAPbX3 (MA=CH3NH3+; X=Cl, Br, I) have aroused great interests due to their excellent photoluminescence and light-absorbing ability1. In particular, since Miyasaka’s group reported the first perovskite sensitized solar cell in 20092, we have witnessed rapid evolution and great breakthrough in solar cells where organic-inorganic hybrid perovskites serve as light absorbers, accomplishing a power conversion efficiencies of 22%.3,4 Besides, PNCs with most intriguing luminescent properties and high PLQYs as well as narrow-band emissions, have also been widely regarded as promising candidates of next generation display devices.5-7 Formamidinium lead halide pervskites FAPbX3 (X=Cl, Br, I) as new emerging direct bandgap material have earned great reputation for its better thermodynamic stability than those of MAdirecting perovskites. It has been also regarded as a potential candidate for optoelectronic devices8-12. Recently, much efforts have been done for efficient PNCs synthesis, involving hotinjection,13,14 ligand-assisted reprecipitation (LARP),15,16 or the other.17 The FA lead halide perovskites feature better stability towards heat, moisture and chemicals8,18-22, which stimulates


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research interests to focus on FA-directing PNCs. Recently, Kovalenko’s group firstly synthesized FAPbX3 perovskites possessing bright photoluminescence and tunable wavelength at high temperature.23 However, the reaction temperature may fluctuate when injecting the cold precursor solution. Also, it may result in a bad quality control and hinder the stable preparation of FAPbX3 on a large scale. To solve it, much efforts have been devoted to developing a roomtemperature synthetic method24-26. For the room-temperature preparation, lead halides (PbX2; X = Cl, Br, I) are usually employed as the raw materials, while N, N-dimethylformamide (DMF) serves as the solvent. Unfortunately, DMF may corrode the structure of perovskites, giving rise to an unavoidable deterioration of product yields27. Hence, it is still a significant challenge in synthesizing superior FAPbX3 (X=Cl, Br, I) PNCs on a large scale at ambient temperature. In this context, we proposed a facile strategy to synthesize FAPbBr3 through a one-step homogeneous reaction at ambient temperature. First, FA and Pb precursor solution was prepared by dissolving formamidine acetate and PbO into excessive oleic acid, serving as capping agents. Then, Br precursor solution consisting of tetraoctylammonium bromide, oleic acid and toluene was quickly poured into the FA and Pb precursor solution. As a result, the mixed solution became bright green without any aggregation immediately, indicating the formation of wellcrystalline PNCs. Next, anion-exchange reactions were adopted to tune the anion composition of PNCs, resulting in a series of PNCs with emission spanning the visible region. It is suggested that initial PNCs serves as a template whose size and composition can be well modified. Comparing with ligand-assisted reprecipitation method synthesis of monodisperse FAPbX3 PNCs, this method is more convenient and versatile for the fabrication of FAPbBr3 PNCs. More importantly, the preparation of FA precursor is much easier, without heating and laborious procedures by simply using commercially available inexpensive formamidine acetate as FA


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precursor in our case. Finally, we further fabricated efficient wide-color gamut LCD backlight with color gamut of 116% NTSC. The performance is superior than that of the reported allinorganic CsPbBr3 PNCs based LCD5,6, showing the potential for display backlights. EXPERIMENTAL METHODS Materials Formamidine acetate, lead oxide (PbO, 99.9%), lead iodide (PbI2, 99.9%), lead chloride (PbCl2, 99.9%), tetraoctylammonium bromide (C32H68BrN, 98%), oleic acid ( ≥ 90%) and poly(methyl methacrylate) (PMMA, average Mw∼35000) were purchased from Aladdin Chemistry Co., Ltd. and used without further treatment. Toluene (analytical grade) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Preparation of mixed FA-oleate and Pb-oleate precursor solution Firstly, 1.0 mmol PbO and 1.0 mmol formamidine acetate were mixed with 5.0 mL oleic acid in a glass vial. In the next operation, the mixture was placed on a hot plate preheated to 160 oC and magnetically stirred until the mixture transformed into a homogenous and transparent solution. Then, the FA and Pb precursor solution was thoroughly dehydrated in a 120 oC vacuum drying chamber. For further utilization, the FA and Pb precursor solution was diluted to 0.1 M with toluene as solvent and the dilute precursor solution was sealed and stored in a glass bottle. It is worth noting that the whole preparation process of FA and Pb precursor was carried out in the open air. Small-scale synthesis of FAPbBr3 PNCs In a typical procedure, 1.0 mL FA and Pb precursor solution was blended with 15.0 mL toluene and stirred vigorously at room temperature to obtain homogeneous solution. Then, a Br


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precursor was prepared by dissolving 0.1 mmol tetraoctylammonium bromide and 0.5 mL oleic acid into 2.0 mL toluene. Finally, the Br precursor was poured into the FA and Pb precursor solution swiftly and the mixture turned into a clear and bright green solution immediately, indicating the formation of FAPbBr3 PNCs. Afterwards, the γ-butyrolactone was applied as precipitator to separate out the FAPbBr3 PNCs. Finally, the pure FAPbBr3 PNCs was obtained by highly-speed centrifugation and redispersed in toluene for property examination. Note that the crude solution of PNCs was used for long-term storage. Synthesis of alloyed FAPbX3 (X=Cl, Br, I) PNCs First, the FAPbBr3 PNCs with oleic acid capping were prepared in toluene. Subsequently, the various quantities (normally ranging from 1 to 2 mmol) of PbCl2 or PbBr2 were dropped into the crude solution of FAPbBr3 PNCs (10 mL toluene) until the desired emission peak position was achieved. Large-Scale synthesis of FAPbBr3 PNCs First, 50 mL of oleic acid was used to dissolve 2.5 mmol formamidine acetate and 5.0 mmol PbO in a 0.5 L of beaker, followed by a drying process in a 120 oC oven for 30 min. The prepared FA and Pb precursor solution was diluted by adding 500 mL toluene. Then, 5.0 mmol tetraoctylammonium bromide was dissolved into 40 mL toluene under fierce magnetic stirring, resulting in a Br precursor. Finally, the Br precursor solution and 10 mL oleic acid were blended with FA and Pb precursor solution quickly. Within few seconds, the mixed solution (~0.5 L) containing fine PNCs was accomplished. The yield was estimated by precipitating 2.0 mL of PNCs crude solution in a pre-weighted centrifuge tube. Fabrication of color-converting films with FAPbBr3 PNCs


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In order to fabricate color-converting films, as-prepared FAPbBr3 with bright green emission and K2SiF6:Mn4+ phosphors with red emission were employed as photoluminescent substances. Generally, a red fluorescent coating was first prepared by mixing 0.3 g K2SiF6:Mn4+ phosphors with 2.5 g transparent optical coating and 0.2 g curing agent. Then, with the assistance of an auto-coating technique, as-prepared red fluorescent coating was painting on the surface of a hydrophilic-treated polyethylene glycol terephthalate (PET) substrate at a constant speed of 600 mm min-1. Afterwards, the red fluorescent film was further coated with transparent optical resin containing FAPbBr3/PMMA hybrid materials. Finally, for further use as LCD backlight film, the prepared film was cured in a vacuum drying chamber at 120 oC for 1 hour. The CdSe@ZnS NCs film was synthesized by a similar method. Fabrication of FAPbBr3-directed WLED In the first step, 0.05 g FAPbBr3/PMMA nanocomposites with green fluorescence and 0.025 g (Sr,Ca) AlSiN3:Eu2+ phosphors with red emission were mixed with 0.5 g optical silicone (OE6550A:OE-6550B = 1:1). Then, the mixture was placed in a vacuum oven to eliminate the bubbles for next step use. These FAPbBr3/(Sr,Ca)AlSiN3:Eu2+/silicone mixture was coated on the blue GaN-based LED chips. Afterwards, the chips were thermal cured at 120 oC for 1 h. Finally, a WLED device was constructed by attaching the prepared chips on the bottom of the LED bases. A ZWL-600 instrument (ZVISION Co., LTD) with an integral sphere was used to measure the relevant optical performances. Fluorescent patterns from perovskite via inkjet printing We chose the as-prepared FAPbBr3 PNCs solution as the “ink”, which can be used to print multifarious fluorescent patterns via inkjet printing. The FAPbBr3 PNCs ink was then injected


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into a printer, and finally, legible “auspicious dragon” pattern with bright green photoluminescence was successfully painted on the paper. Characterizations. The particle sizes and crystal lattice of PNCs were examined with a JEOL JEM-2100 transmission electron microscope (TEM). The element analysis of PNCs was obtained by Energy dispersive X-ray spectroscopy (EDS). Fourier-transform infrared (FT-IR) spectra were recorded on a Nicolet 6700 FT-IR spectrometer. A Perkin-Elmer Lambda 900 UV-vis spectrometer was employed to record the adsorption of PNCs solution. X-ray diffraction (XRD) was performed on a Rigaku Corporation D/max-rC rotating anode X-ray powder diffractometer using a copper target. Photoluminescence (PL) spectra were carried out on a Varian Cary Eclipse spectrophotometer at room temperature. Time-correlated single-photon counting (TCSPC) data was measured on the leica SP5 FLIM system using a 405 nm laser as the excitation source. The quantum yields were examined by an Edinburgh FLS920. The emission spectrum of the white LED was characterized by a USB 4000 Miniature Fiber Optic Spectrometer of Ocean Optics. All the spectra were obtained at room temperature. RESULTS AND DISCUSSION Traditional preparation methods of FAPbBr3 PNCs highly rely on complicated and inhomogeneous reactions, which is subject to outputs costly and limits further amplified fabrication. By virtue of the high localization of the injected agents, the quality and dispersity of products may suffer from degradation. Herein, we report a facile and high-yield fabrication of FAPbBr3 PNCs with fine optical properties. A typical synthesis process of FAPbBr3 is illustrated in Scheme 1. In the first procedure, a mixture of formamidine acetate, PbO and oleic acid was dissolved into non-polar solvent toluene and magnetically stirred at 160 oC for 5 min to form a


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clear precursor solution. Then, a Br precursor solution prepared with tetraoctylammonium bromide, oleic acid and toluene was poured into FA and Pb precursor swiftly. Immediately, a green colloidal solution was formed. Excessive oleic acid utilized in the preparation process may result in an efficient chemical passivation on the surface of FAPbBr3 PNCs, bringing out good colloidal stability and highly bright luminescence with PLQY up to 76%. This method is feasible to produce FAPbBr3 solution on a large scale (~0.5 L). More importantly, the fabrication process was implemented in open air, avoiding harsh operating conditions. Besides, the as-prepared PNCs solution is highly transparent, which verifies the high dispersity of PNCs without obvious aggregation.

Scheme 1. Schematic diagram of one-step large-scale synthesis for colloidal FAPbBr3 PNCs and their versatile applications.


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As shown in Figure 1a, the morphology and size of FAPbBr3 PNCs were characterized by transmission electron microscopy (TEM). Typical cubic shape of FAPbBr3 PNCs is clearly observed and a statistic analysis of PNCs size validates that they have a mean size of 8.28 nm with a standard deviation of 1.5 nm. Moreover, high-resolution TEM (HRTEM) image of single FAPbBr3 particle demonstrates an obvious lattice stripes, proving the well-defined crystalline structure of PNCs (Figure 1b). The distance between adjacent stripes is 0.3 nm, which is in consistent with the (002) crystal face of the cubic PNC24. From the XRD patterns (Figure 1c), we observed obvious diffraction peaks (001) 、 (011) 、 (002) 、 (012) 、 (112) 、 (022) and (003) peaks, revealing the cubic crystal structure of FAPbBr3 PNCs23. Energy dispersive X-ray spectroscopy (EDS) was also performed to implement compositional analyses of the sample (Figure 1d). EDS shows that the Pb: Br molar ratio of FAPbBr3 PNCs is 1: 2.9 (mol/mol) (see Table S1), which isn’t seriously in agreement with stoichiometric ratio of 1: 3. The nonstoichiometric composition of PNCs are usually attributed to the anion or cation rich surface.


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Figure 1. (a) TEM micrograph of the monolayer FAPbBr3 PNCs on a grid (insert: the corresponding partical size histogram of the FAPbBr3 PNCs). (b) HRTEM of single FAPbBr3 PNCs. (c) XRD pattern of FAPbBr3 PNCs. (d) EDS analysis of FAPbBr3 PNCs. We further investigated the optical properties of colloidal FAPbBr3 PNCs. Both the absorption spectrum (red line) and emission spectrum (black line) of FAPbBr3 PNCs are demonstrated in Figure 2a. From the UV-vis absorption spectrum, an absorption peak is observed around 500 nm. Additionally, a sharp emission peak with narrow FWHM (20 nm) appears at 518 nm in PL spectrum, which notarizes an excellent PL property of FAPbBr3 PNCs. Low temperature solution process usually accounts for a high density of structural defects and trap states.28 However, the as-prepared colloidal FAPbBr3 PNCs exhibit relatively high PLQY of 76% at room temperature, which is comparable to the coated chalcogenide NCs.29,30 Such high PLQY is attributed to the reduction of nonradiative decay in FAPbBr3 PNCs. We further studied the time-resolved photoluminescence decay of FAPbBr3 PNCs based on the exciton recombination dynamics.16 The decay trace of FAPbBr3 PNCs is well fitted with biexponential function to calculate an average lifetime (see equations 1, 2 in supporting information). As seen in Figure 2b, the calculated PL lifetime of the FAPbBr3 PNCs is 13.2 ns on the basis of the time-resolved PL decay curve of the FAPbBr3 PNCs.


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Figure 2. (a) UV−vis absorption (red line) and PL emission (black line) spectra (λex = 365 nm) of FAPbBr3 PNCs in toluene. (b) Time-resolved fluorescence decay curves of FAPbBr3 PNCs. Postsynthetic chemical transformations of PNCs, especially anion-exchange reactions, have been widely reported.16,31,32 The anion-exchange process was carried out in toluene by blending as-prepared FAPbBr3 and either PbX2 (X=Cl, I) in a specific molar ratio. Because of the ionic conductivity of halides, the reaction can reach to a balance within several minutes33. The optical images of various PNCs under visual light and UV light are shown in Figure 3a. It is obvious that the postsynthetic anion-exchange reactions give rise to a red shift (from Br− to I−) and a blue shift (from Br− to Cl−). The shifts of emission peaks can be ascribe to the replacement of anions (Br−) with other halide ions (Cl− or I−), which may lead to a transformation of chemical composition and particle size. Taking full advantage of anion exchange reactions, we have prepared five kinds of PNCs with narrow FWHMs (20~40 nm) and emissions ranging from 452 nm to 646 nm, which almost overlaps with the entire visible spectral region (Figure 3b). In order to investigate the evolution of crystal structure after anion-exchange reaction, XRD patterns of various anion composition PNCs are displayed in Figure 3c. By comparisons between various XRD patterns, it can be found that the XRD patterns almost remain unchanged, which implies that the geometry and perovskite phase of FAPbBr3 template is maintained regardless of the low reaction temperature. Accordingly, it can be further deduced the replacement of anions from the lattice parameters change. Moreover, FT-IR spectra were recorded to investigate the chemical composition of PNCs (Figure S1). The peak at 1716 cm-1 is corresponding to the symmetric stretch of C=N of FA+, which implies the stable existence of FA+ during the process of anion exchange.


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The PLQYs of various PNCs is presented in Figure 3d. Obviously, the highest PLQY value of 76% is achieved by FAPbBr3. By contrast, both the FAPb(Cl/Br)3 and FAPb(I/Br)3 exhibit a lower PLQY that decrease with the increment of mixed anion. This phenomenon may be ascribe to the metastable state of mixed-anion PNCs, which may suffer from degradation and phase separation. Time-resolved photoluminescence decays of different anion-compositional PNCs indicate average lifetimes from 6 ns to 22 ns (Figure 3e). Obviously, the lifetimes of FAPb(Br/I)3 is increased with I− ions concentrations, whereas the lifetimes of FAPb(Br/Cl)3 decreased with the increment of Cl− ions concentrations. The above results indicate that our anion-exchanges samples are comparable to that of direct synthesized mixed-halides FAPbX3 samples.

Figure 3. (a) The photographs of various PNCs with different doped anions under visible light (left) or UV light (right). (b) Evolution of the optical absorption (solid lines) and PL (dashed lines) spectra of FAPbBr3 PNCs with the increasing quantities of PbX2 (X=Cl, I), added as ionexchange sources. (c) XRD curves for single and mix-halide FAPbX3 PNCs. (d) The PLQYs of


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PNCs with various mix-halide ratio. (e) Evolution of the time-resolved PL decay spectra of FAPbBr3 PNCs and mixing with either PbCl2 or PbI2 PNCs at various ratios. As discussed above, we have designed a feasible route to synthesize high PL intensity PNCs with tunable wavelength on a large scale, which lays a solid foundation for the practice of PNCs as color-converting materials in LCD backlight. In the first procedure, large amount of green FAPbBr3 PNCs was fabricated on a large scale via a one-step homogenous reaction (Figure 4a). Then, a nanocomposites by embedding the PNCs into PMMA matrix was uniformly coated on the transparent PET film (Figure 4b), resulting in a fluorescent film. As shown in Figure 4c, this film is transparent enough to see the luminous “Perovskite” characters. When lighting with 460 nm emission blue backlight deriving from the LCD (Founder technology Group Co., LTD), the film exhibits a bright green photoluminescence (Figure 4d). A red emission K2SiF6:Mn4+ phosphors with narrow FWHM of 10 nm was employed as another fluorescent materials to incorporate with FAPbBr3 PNCs, fabricating a color-converting film. An EL spectrum was used to investigate the optical property of this film in Figure 4e. Three peaks in the EL spectrum are attributed to blue backlight (450 nm), green perovskites (518 nm) and red phosphors (630 nm), respectively. All of these peaks show narrow FWHMs, which give rise to a wide color gamut of 116% according to NSTC 1931 standard (Figure 4f). A photograph of a display is shown in Figure 4g, which only demonstrates a blue light. Then, as illustrated in Figure 4h and 4i, the display exhibits legible and colorful images with assistance of cadmium base NCs film (Figure 4h) and FAPbBr3 PNCs film (Figure 4i). By comparison, it could be found that the FAPbBr3 PNCs film shows a higher brightness and color saturation than those of traditional cadmium base NCs film. Additionally, the stability of PNCs in film is a very important parameter for practical applications. Benefiting from the encapsulation of PMMA matrix, the PNCs can preserve their


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superior PL intensity and high PLQY. But the stability of FAPbBr3 PNCs in the long-term need highly improving in the future. Therefore, the FAPbBr3 PNCs may be superb material candidates applied in the field of display.

Figure 4. Schematic illustration of the process for large-scale synthesis of FAPbBr3 PNCs (a) and FAPbBr3 PNCs film (b). Digital photograph of the FAPbBr3 PNCs film under room light (c) and UV light (d), respectively. (e) EL spectrum of the device operated with operating current of 350 mA. (f) The color gamut of the LCD film in comparison with the standard of 1931 NTSC. The pictures of the LCD without color-converting film (g), with the CdSe@ZnS NCs film (h) and with the FAPbBr3 PNCs film (i), respectively. Finally,

a

WLED

was

successfully

constructed

by

coating

the

FAPbBr3/

(Sr,Ca)AlSiN3:Eu2+/PMMA mixture on a blue GaN-chip (Figure 5a). When supplied with enough power, the as-prepared WLED gives out bright white light (Figure 5b). As shown in Figure 5c, a pattern of LED was lighted up with this WLED, which verifies the potential practice of FAPbBr3-based WLED. Furthermore, the EL spectrum of WLED device (Figure 5d) reveals three peaks (blue, green, red), which originate from blue GaN-chip, green FAPbBr3 and red


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(Sr,Ca)AlSiN3:Eu2+ phosphors, respectively. More importantly, the WLED possess a color coordinates of (0.35, 0.32) located in a region of white light color according to the CIE chromaticity diagram (Figure 5e). A high color rendering index of 87.5 was realized by virtue of the narrow FWHM of FAPbBr3 PNCs. On the basis of above discussion, the FAPbBr3-based WLED shows a great potential for the next generation luminous devices. Besides, FAPbBr3 PNCs with superior photoluminescence can also play a role as the ink for inkjet printing. As illustrated in Figure 5f, the FAPbBr3 PNCs in ink was deposited on the substrate and formed a complicated pattern via an inkjet printer. For a proof to concept, a fluorescent “auspicious dragon” pattern was printed with legible and well-defined boundaries, which validates the potential application of FAPbBr3 PNCs as fluorescent ink to fabricate UV-visible pattern.


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Figure 5. Digital photographs of WLED device with power off (a) and on (b). (c) A picture with bright illumination supplied by the WLED. (d) The EL spectrum of WLED under an applied current of 350 Ma. (e) CIE 1931 chromaticity diagram of the FAPbBr3-based WLED device. (f) Schematic diagram of the process for the inkjet printing. (g) A fluorescent pattern prepared by inkjet printing. CONCLUSIONS In summary, we report a one-step and homogenous method to synthesize highly luminescent FAPbX3 PNCs at room temperature on a large scale (~0.5 L). The as-prepared PNCs possess superior photoluminescence with a high PLQY up to 76% and a narrow FWHM of 20 nm. Additionally, a series of PNCs with tunable PL wavelengths ranging from 452 to 646 nm are prepared by adjusting the dose of PbCl2 or PbI2 via a facile anion-exchange process. Through making best of superb fluorescent property of FAPbBr3 PNCs, it could be regarded as colorconverted materials for LCD backlights with wide color gamut (116% of NTSC standard). Comparing with cadmium base NCs film, PNCs film exhibit high color saturation and lightconverted efficiency. Besides, a white LED based on the FAPbX3 PNCs was fabricated successfully, which demonstrates a color coordinate of (0.35, 0.32) near the standard coordinate (0.33, 0.33). Finally, the PNCs solution served as an ink for inkjet printing to fabricate complicated pattern, which may be used in anti-counterfeiting and fluorescent code. In a word, our research might not only open a facile and feasible avenue to obtain FAPbX3 PNCs in largescale and reveals their versatile potential applications for various optoelectronic devices. ASSOCIATED CONTENT


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The Supporting Information is available free of charge on the ACS Publications website or from the author. AUTHOR INFORMATION Corresponding Author *Corresponding

author:

Tel:

86-25-83172258,

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86-25-83172258.

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[email protected]. Notes The authors declare no competing financial interest. ACKNOWLEDGMENTS This work was supported by National Natural Science Foundation of China (21736006, 21474052), the National Key Research and Development Program of China (project No. 2016YFB0401700), the Natural Science Foundation of Jiangsu Province (BK20171013), Fund of State Key Laboratory of Materials-Oriented Chemical Engineering (ZK201704, ZK201716) and Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD). REFERENCES (1) Bai, S.; Yuan, Z. C.; Gao, F. Colloidal Metal Halide Perovskite Nanocrystals: Synthesis, Characterization, and Applications. J. Mater. Chem. C 2016, 4 (18), 3898-3904. (2) Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T. Organometal Halide Perovskites as Visible-light Sensitizers for Photovoltaic Cells. J. Am. Chem. Soc. 2009, 131, 6050-1.


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TOC

FAPbBr3 perovskite nanocrystals have been successfully synthesized via a one-step homogeneous process on a large scale towards high performance display.


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One-Step Synthesis of FA-Directing FAPbBr3 Perovskite Nanocrystals

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