Super-Hydrophobic Cesium Lead Halide Perovskite Quantum Dot

Subscriber access provided by UNIV OF NEW ENGLAND ARMIDALE

Article

Super-Hydrophobic Cesium Lead Halide Perovskite Quantum Dots-Polymer Composites with High Stability and Luminescent Efficiency for Wide Color Gamut White Light-Emitting Diodes Tongtong Xuan, Junjian Huang, Huan Liu, Sunqi Lou, Luyu Cao, Weijiang Gan, Ru-Shi Liu, and Jing Wang Chem. Mater., Just Accepted Manuscript • DOI: 10.1021/acs.chemmater.8b04596 • Publication Date (Web): 17 Jan 2019 Downloaded from http://pubs.acs.org on January 17, 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 9 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

Chemistry of Materials

Super-Hydrophobic Cesium Lead Halide Perovskite Quantum DotsPolymer Composites with High Stability and Luminescent Efficiency for Wide Color Gamut White Light-Emitting Diodes Tongtong Xuan,†,# Junjian Huang,†,# Huan Liu,┴ Sunqi Lou,† Luyu Cao,† Weijiang Gan,† Ru-Shi Liu‡,‖,*Jing Wang†,* †Ministry

of Education Key Laboratory of Bioinorganic and State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry, School of Materials Science and Engineering, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China ‡Department

of Chemistry, National Taiwan University, Taipei 106, Taiwan

‖Department

of Mechanical Engineering and Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 106, Taiwan ┴Key

Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, China

ABSTRACT: We present a novel composite strategy to enhance the stability of water-sensitive CsPbBr3 quantum dots (QDs) by embedding the QDs into the super-hydrophobic porous organic polymer frameworks (CPB@SHFW). The CPB@SHFW composites not only preserve a high photoluminescence quantum yield (PLQY ~ 60%) and narrow band emission (full width at half maximum ~ 16 nm) but also inherit the outstanding water-resistant property of SHFW to protect the QDs from hydrolytic degradation. The PLQY of the composites was maintained at 91% (PLQY~54.3%) of the initial one (PLQY~60%) after being immersed in water for 31 days. Even being immersed in water for 6 months, the CPB@SHFW composites still retain bright green emission. In addition, super-hydrophobic perovskite QDs-polymer composites (IPQDs@SHFW) with tunable and bright emission were prepared by using suitable halide salts. A white emitting-diodes (WLED) device was prepared by combining green-emitting CPB@SHFW composites and red-emitting K2SiF6:Mn4+ phosphors with a blue LED chip. The device exhibits a high luminous efficiency of 50 lm/W, and a wide color gamut (127% of NTSC and 95% Rec. 2020). This work provides an alternative approach to solve the challenging stability issue of perovskite QDs, therefore it has a positive implication toward their practical application in liquid crystal display backlights.

INTRODUCTION All inorganic lead halide perovskite quantum dots (IPQDs), CsPbX3 (X = Cl, Br, I), have been attracting increasing attention for their excellent optical properties, such as tunable emission wavelength, high photoluminescence quantum yield (PLQY), narrow full width of half maximum (FWHM), and high defect tolerance.1-4 Therefore, the IPQDs have potential application in solar cells, light emitting diodes (LEDs), and lasers.5-9 Unfortunately, the IPQDs suffer from poor stability due to the hydrolytic degradation, which limits their practical applications.6, 10-14 Up to now, great efforts worldwide have been made to face the moisture-sensitive problem of the perovskite QDs. Among previous reports, the water-resistant organic ligands, polymers or silicon dioxide were coated on the surface of the perovskite QDs as protecting layer by ligands

exchanging or encapsulation to enhance water stability, as shown in Figure S1.11-12, 15-26 For example, Huang et al. coated polyhedral oligomeric silsequioxane (POSS) on the surface of CsPbX3 QDs with enhanced hydrolytic resistance. Lin et al. reported the encapsulation of the perovskite QDs in polystyrene with bright emission and enhanced the waterresistant property.27 Moreover, atomic layer deposition for the growth of the amorphous alumina matrix on CsPbBr3 QDs was proved to exceptionally improve stability towards exposure to air, and even upon immersion in water for a short time.17 The main idea of the previous work is focused on the water-resistance of organic or inorganic coating layer themselves but not their microstructure (Figure S1). Instead, we proposed a new super-hydrophobic structure concept to enhance the water stability of perovskite QDs, which is rarely reported in previous work.

ACS Paragon Plus Environment

Chemistry of Materials 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

Super-hydrophobic materials have been extensively applied to a broad range of fields due to the unique waterrepellent property that water contact angles (CA) greater than 150°.28-30 The super-hydrophobic surfaces generally arise from their hierarchical pore structures from nanometer to micrometer scales. Recently, porous organic polymers (POPs) have been developed as a new platform to construct hierarchical porous frameworks in the presence of the suitable pore-making agent, which results

to super-hydrophobic property.31-32 Due to the superhydrophobicity and the hierarchical porous structure of the POPs, we envision that whether the moisture-sensitive IPQDs can be absorbed into the POPs forming composites. The composites not only preserve the excellent optical properties of the IPQDs but also inherit the outstanding super-hydrophobicity of the POPs to resist the hydrolytic degradation.

Figure 1. The schematic illustration for preparation CPB@SHFW composites.

Here, we report a novel strategy (Figure 1) to enhance a water-resistance property of the CsPbBr3 QDs by absorbing the QDs into super-hydrophobic POPs frameworks (SHFW) and forming super-hydrophobic composites (CPB@SHFW). The composites exhibit excellent optical property and surprising water-resistant property. The divinylbenzene (DVB), ethyl acetate and azodiisobutyronitrile (AIBN) were chosen as monomers, pore-making agent, and initiator for preparation of SHFW with a pore size of approximately 10-100 nm, respectively. Therefore, the CsPbBr3 QDs can be easily adsorbed into the pores of the SHFW forming CPB@SHFW composites. Based on these stages, super-hydrophobic perovskite composites (IPQDs@SHFW) with tunable emission can be simply obtained by using suitable halide salts. The composites not only exhibit bright emission, high color purity but also present good water-resistant property even when being immersed in water for 6 months. These indicate they have great potential applications in white light-emitting diodes (WLEDs) for backlight display.

RESULTS AND DISCUSSION The SHFW was synthesized by a simple solvothermal method33, and the details were described in the Supporting Information. It should be noted that the SHFW was washed by chloroform to remove unreacted reagents,

which is a vital procedure to retain its superhydrophobicity in high humidity atmospheres. As shown in Figure S2, the solid-line marked peaks at around 1635 cm-1 and 3085 cm-1 in the infrared absorption spectra were attributed to the C=C bonds and stretching vibrations of CH of DVB, respectively. Their relative intensity distinctively weakened after the polymerization process, which indicates the success of this cross-linking reaction. Table S1 shows the nitrogen sorption isotherms of the SHFW. The SHFW exhibits a large BET specific surface area (724.3 m2g-1), a large pore volume (1.8 cm3g-1), as well as large pores (10-100 nm) distribution (Figure S3). As shown in Figure S4 and Figure S5a-b, the morphology of the SHFW was characterized by using transmission electronic microscopy (TEM) and scanning electron microscope (SEM), which further confirms their hierarchical porous structure. Additionally, the super-hydrophobicity was verified by the drop shape analyzer with a water CA approximately equal to 150° (Figure S4c). The SHFW not only has the suitable hierarchical porous structures but also exhibits the excellent water-resistant property. Therefore, we expected it was appropriate for the SHFW to absorb suitable IPQDs to enhance their water stability and retain their excellent optical property.


Page 2 of 9

Page 3 of 9 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. (a) Schematic of CPB@SHFW composites. The XRD patterns (b) and BET curves (c) of SHFW and CPB@SHFW composites, respectively. (d) The SEM image of CPB@SHFW composites. The inset in the top right corner is the image of the composites under 365 nm UV light and the bottom right corner is the image of a water droplet on their surface. (e) The TEM image of the composites. The inset in the top right corner is the HR-TEM images. (f) The PL spectra of SHFW, CsPbBr3 QDs, and CPB@SHFW composites, respectively.

Green emitting CsPbBr3 QDs were synthesized by a traditional hot-injection method.34 As shown in Figure S6, the QDs exhibit cubic shape with an average particle size of 18 nm, which was smaller than the pores of the SHFW. Thus, it was suitable for the absorption into the SHFW. Figure 2a shows the schematic of CPB@SHFW composites. The CsPbBr3 QDs were absorbed into the surface pores of the SHFW and gradually moved to the inside pores of the SHFW forming CPB@SHFW composites. The XRD patterns of SHFW and CPB@SHFW were shown in Figure 2b, which indicates the CsPbBr3 QDs were successfully composited with the SHFW. To further confirm the CsPbBr3 QDs absorbed in SHFW, SEM and TEM were used to observe their morphology and structures. As seen from the SEM images (Figure 2d, Figure S5c-d), the CPB@SHFW composites show hierarchical porous structures, which is similar to that of the pure SHFW (Figure S4b, Figure S5ab).33, 35 The TEM image (Figure 2e) of the composites with light and shade the contrast shows that the QDs mainly distributed in the SHFW. As shown in Figure S7a, the high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) image illuminates that the heavier elements (Pb) were completely wrapped by the carbon of the SHFW. The EDS mapping image (Figure S7cf) further demonstrates that the elemental distribution of Cs, Pb, and Br are well-distribution. Meanwhile, highresolution TEM (HR-TEM) image of the embedded QDs (Figure 2e inset) shows the lattice spacing of 0.29 nm, which corresponds to the (200) plane of the cubic-phase CsPbBr3. Combined with these results and analyses, we can

safely conclude that the CsPbBr3 QDs absorbed into SHFW forming CPB@SHFW composites. In addition, the further BET, optical, and water stability measurements indirectly confirm the good distribution of CsPbBr3 QDs in the framework of the SHFW as discussed below. To investigate the surface pore structure of CPB@SHFW composites, the nitrogen sorption isotherms were used to verify their hierarchical porosity. The nitrogen absorption/desorption isotherms patterns of SHFW and CPB@SHFW (Figure 2c) both behaved like a typical H4 hysteresis loop, which could be refereed to their hierarchical porosity. A slow increasing in the absorption amounts in the relative pressure range of 0.4-0.8 indicates the presence of mesopores, and a dramatically increasing at high relative pressure (>0.9) verifies the presence of large pores. Table S1 and Figure S3 reveal that although BET specific surface area and aperture base on BarrettJoyner-Halenda (BJH) measurement decreases from 724 to 303 m2/g, and 75 to 51 nm respectively due to the absorption of CsPbBr3 QDs in the pores of SHFW, their porosity was well retained after the composite procedure. The CPB@SHFW composites exhibit pore size distribution from 10 nm to 100 nm with a main pore diameter of 51 nm, which is smaller than the critical bore diameter (100 nm) of super-hydrophobic structure.(More details in the Supporting Information)30, 36 This indicates that the CPB@SHFW composites may inherit the superhydrophobicity property of the pure SHFW. The superhydrophobicity property of the CPB@SHFW composites



was further verified by the drop shape analyzer with a water CA of 150° (the inset bottom right corner of Figure 2d), which is equal to that of the pure SHFW (Figure S4c). These illuminate that our prepared CBP@SHFW

composites retain the super-hydrophobicity property of the SHFW. In addition, the composites exhibit superhydrophobicity property even at high temperature (Figure S8).

Figure 3. (a) The PLQY of CPB@SHFW composite powders as a function of time in water (inset: the CA images of before and after being immersed in water for 31 days). (b) The photographs of CPB@SHFW composite powders immersed in water for 3 months and 6 months under white light and 365 nm UV light, respectively. (c) The photographs of blue, green, and red emitting IPQDs@SHFW composite powders, and the images of water drop on the composite films under white light and 365 nm UV light, respectively. (d) The PL spectra of the IPQDs@SHFW composite powders.

We further investigated the photoluminescent property of the CPB@SHFW composites. As-prepared sponge-like CPB@SHFW composite powders exhibit bright green emission under excitation of 365 nm UV light (the inset top right corner of Figure 2d). The PL spectra of SHFW, CsPbBr3 QDs, and CPB@SHFW were shown in Figure 2f. The SHFW shows no emission in the range 480 nm to 580 nm. After centrifugal separation, the pure CsPbBr3 QDs powders exhibit much weak green emission with the PLQY of almost about zero even though the PLQY of the CsPbBr3 QDs solution was high up to about 80%. Very interestingly, the CPB@SHFW shows the standard spectra of CsPbBr3

QDs at 518 nm with an FWHM of 16 nm and a high PLQY of about 60% (Figure S9), which strongly suggests that the CsPbBr3 QDs have good distribution in the framework of the SHFW.23, 37 Most probably, more than one CsPbBr3 QDs distribute inside one pore of the SHFW because the size of the pores of CPB@SHFW is about ~75 nm, larger than the 18 nm of one CsPbBr3 QDs. To further understand the high PLQY of the CPB@SHFW composites, we investigated the lifetime change of the CsPbBr3 before and after absorbed into the SHFW. Figure S10 shows the PL decay curves of the CsPbBr3 QDs and CPB@SHFW composites, which were


Page 4 of 9

Page 5 of 9 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

Chemistry of Materials fitted by a two-exponential function (Table S2). The corresponding average lifetimes were 7.9 and 12.8 ns, respectively. The increased lifetime illustrates that the CsPbBr3 QDs embedded into the SHFW does not trigger more non-radiative decay and the generated excitons tend to recombine with radiative path, which is in coincidence well with the high PLQY.17, 38

light radiation (λpeak=455 nm, 6W). As shown in Figure S11, after being radiated under blue light for 24 h, the PL intensity of the composites retains 58.6% of the initial one, which is much higher than that of the pure CsPbBr3 QDs (24.6%). Probably, the existence of the SHFW framework slows down the decomposition of the embedded CsPbBr3 QDs, which is similar as that of the SiO2 and Al2O3.17, 39

Although as-prepared CPB@SHFW composite powders exhibit super-hydrophobicity property and bright emission, the water stability is still unclear. To evaluate the water stability of the CPB@SHFW composites, the composites were directly immersed in water (The experimental details were described in Supporting Information). Interestingly, when the composites immersed into the water without vigorous vibrating, they immediately floated on the surface of the water with a clear boundary (Figure 3b) due to the super-hydrophobicity property. The PLQY of the composites was maintained at 91% (PLQY~54.3%) of the initial one (PLQY~60%) after being immersed in water for 31 days as shown in Figure 3a. Moreover, the composites still show strongly emissive after being immersed in water for 6 months (Figure 3b). It should be mentioned that the CA of the composites still maintains 150º after being immersed in water for 30 days. These illustrate that the CsPbBr3 QDs were indeed absorbed into the SHFW forming CPB@SHFW composites, which exhibits excellent water stability resulting from the super-hydrophobicity property of the composites. The super hydrophobic structure can resist water away from the CsPbBr3 QDs to avoid the hydrolytic degradation. We further investigated the PL stability of CsPbBr3 QDs and the CPB@SHFW composites under blue

In addition, the blue emitting CsPbCl1.5Br1.5@SHFW and red emitting CsPbBr1.2I1.8@SHFW composite powders were prepared by the similar method for the CPB@SHFW. Figure 3c shows the photographs of the blue, green, and red emitting composite powders under daylight and 365 nm UV light and the water drop on their films under 365 nm UV light. The corresponding PL spectra were shown in Figure 3d and centered at 454 nm, 518 nm, and 648 nm with the FWHM of 22 nm, 16 nm, and 35 nm, respectively. As shown in Figure S12, the RGB perovskite QDs powders exhibit water CA of 110°, 102°, and 109°, respectively, which indicates that the pure perovskite QDs show hydrophobic property because of the surface organic ligands, such as oleic acid (OA) and oleylamine (OAm). Comparatively, the water CA of IPQD@SHFW (Figure S13) is greatly larger than that of pure IPQDs, suggesting that the IPQD@SHFW exhibits more super hydrophobic performance than pure IPQDs. Therefore, as-prepared IPQDs@SHFW composites have long time stable super hydrophobic property and high water-stability. Especially, the PLQY of CsPbI3@SHFW composites remains at 65% of the initial PLQY after being immersed in water with vigorous vibrating for 9 days (Figure S14), which illustrates that as-prepared CsPbI3@SHFW composites display greatly enhanced water stability when comparing with the pure CsPbI3 QDs.40-41

Figure 4. (a) The EL spectrum of a WLED based on CPB@SHFW composites, KSF phosphors and a blue LED chip (inset: the photograph of the WLED operated at 20 mA). (b) The color coordinate and the gamut of the WLED.

Compared with the previously reported CsPbBr3-polymer composites (Table S3)15-16, 26-27, 42, our prepared greenemitting CPB@SHFW composite powders display a relatively high PLQY, high color purity, and excellent water stability, which makes them promising for use as green phosphors in wide color gamut display devices. A WLED was fabricated by encapsulating a mixture of greenemitting CPB@SHFW composite powders, red-emitting K2SiF6:Mn4+ (KSF) phosphors and silicone resin onto a blue

InGaN LED chip (λpeak = 447 nm). As shown in Figure 4a inset, the WLED at a driving current of 20 mA generated white emission with a high luminous efficiency of 50 lm/W, and a CIE chromaticity coordinate of (0.329, 0.305) without optimizing the structure of the device, which shows better performance than that of the CsPbBr3 QDs, KSF based WLED (Table S4). The corresponding electroluminescence (EL) spectrum (Figure 4a) obviously consists of three emission band centered at 447 nm, 525



nm, and 630 nm, which belong to the blue LED chip, CPB@SHFW composites, and KSF phosphors, respectively. As shown in Figure 4b, the chromaticity coordinates of RGB were (0.0.155, 0.019), (0.143, 0.763) and (0.691, 0.309), generating a triangle area on the CIE 1931 chromaticity diagram, which was calculated as 127% of National Television System Committee (NTSC) space and 95% of Rec. 2020 space approximately. This result was much better than that of the commercial green phosphors (βSiAlON:Eu2+) and KSF phosphors based WLED, whose NTSC space was merely 89%.22 These indicate as-prepared CPB@SHFW composite powders have great potential as green phosphors for LCD display devices. Besides, the CPB@SHFW composites were demonstrated as water-resistant ink. in the field of fluorescent anticounterfeiting. It is obviously seen in Figure S15 and Video S2 that the “SYSU” characters wrote by either the CsPbBr3 QDs or the CPB@SHFW show bright green fluorescence. Unfortunately, after being immersed in water for about 40 minutes, the CsPbBr3 based “SYSU” exhibits no fluorescence signal. On the contrary, the CPB@SHFW composites based “SYSU” still remains bright green emission under 365 nm UV light after even being immersed in water for about 20 hours. These indicate that our prepared CPB@SHFW composites based fluorescent ink shows high water stability and have potential application in water-resistant fluorescent ink in the field of fluorescent anti-counterfeiting.

CONCLUSION In summary, we present a simple process that enables the CsPbBr3 QDs embedded in the super-hydrophobic framework forming CPB@SHFW composites. The composites not only exhibit bright emission with narrowband emission (FWHM = 16 nm) and a high PLQY up to 60% but also display super water stability due to the superhydrophobicity. The composites still show bright green emission even after being immersed in water for 6 months. Meanwhile, super-hydrophobic blue, green, and red emitting IPQDs@SHFW composite powders were prepared with excellent optical properties and superhydrophobicity by using suitable halide salts. Moreover, a WLED device was successfully fabricated based on green emitting CPB@SHFW composite powders, red emitting KSF phosphors and a blue LED chip. The device exhibits a high luminous efficiency of 50 lm/W, and a wide color gamut (127 % of NTSC, 95% of Rec. 2020). We believe the employment of super-hydrophobic framework to enhance the water stability and retain the excellent optical properties of perovskite QDs will energetically facilitate their practical application.

ASSOCIATED CONTENT Supporting Information is available free of charge via the Internet at http://pubs.acs.org. Experimental details and characterizations (BET, CA, TEM, SEM, PL decays, and PL stability of the SHFW and composites)

AUTHOR INFORMATION

Corresponding Author * E-mail: [email protected] (J. W.) E-mail: [email protected] (R.S. L.)

Author Contributions #These

Notes

authors contributed equally.

The authors declare no competing financial interest.

ACKNOWLEDGMENT This work was financially supported by the NSFCs (51702373, 51772336 and 51572302), National Key R&D Program of China (2018YFB0406800 and 2018YFB0406801), the “973” programs (2014CB643801), Guangdong Provincial Science & Technology Project (2015B090926011, 2017A050501008, and 2013B090800019), Teamwork Projects of Guangdong Natural Science Foundation (S2013030012842) and Guangzhou Science & Technology Project (201807010104). This work was also supported by the Ministry of Science and Technology of Taiwan (Contract No. MOST 107-2113-M-002-008-MY3)

REFERENCES 1. Huang, H.; Bodnarchuk, M.; Kershaw, S. V.; Kovalenko, M. V.; Rogach, A. L., Lead Halide Perovskite Nanocrystals in the Research Spotlight: Stability and Defect-Tolerance. ACS Energy Lett. 2017, 2 (9), 2071–2083. 2. Akkerman, Q. A.; Rainò, G.; Kovalenko, M. V.; Manna, L., Genesis, challenges and opportunities for colloidal lead halide perovskite nanocrystals. Nat. Mater. 2018, 17, 394-405. 3. Kovalenko, M. V.; Protesescu, L.; Bodnarchuk, M. I., Properties and Potential Optoelectronic Applications of Lead Halide Perovskite Nanocrystals. Science 2017, 358 (6364), 745-750. 4. Pan, G.; Bai, X.; Yang, D.; Chen, X.; Jing, P.; Qu, S.; Zhang, L.; Zhou, D.; Zhu, J.; Xu, W.; Dong, B.; Song, H., Doping Lanthanide into Perovskite Nanocrystals: Highly Improved and Expanded Optical Properties. Nano Lett. 2017, 17 (12), 8005-8011. 5. Zhang, M.; Hu, B.; Meng, L.; Bian, R.; Wang, S.; Wang, Y.; Liu, H.; Jiang, L., Ultrasmooth Quantum Dot Micropatterns by a Facile Controllable Liquid-Transfer Approach: Low-Cost Fabrication of High-Performance QLED. J. Am. Chem. Soc. 2018, 140 (28), 8690-8695. 6. Wang, H. C.; Bao, Z.; Tsai, H. Y.; Tang, A. C.; Liu, R. S., Perovskite Quantum Dots and Their Application in Light ‐ Emitting Diodes. Small 2018, 14 (1), 1702433. 7. Chen, X.; Li, D.; Pan, G.; Zhou, D.; Xu, W.; Zhu, J.; Wang, H.; Chen, C.; Song, H., All-inorganic perovskite quantum dot/TiO2 inverse opal electrode platform: stable and efficient photoelectrochemical sensing of dopamine under visible irradiation. Nanoscale 2018, 10 (22), 10505-10513. 8. Pan, G.; Bai, X.; Xu, W.; Chen, X.; Zhou, D.; Zhu, J.; Shao, H.; Zhai, Y.; Dong, B.; Xu, L.; Song, H., Impurity Ions Codoped Cesium Lead Halide Perovskite Nanocrystals with Bright White Light Emission toward Ultraviolet–White Light-Emitting Diode. ACS Appl. Mater. Interfaces 2018, 10 (45), 39040-39048. 9. Bi, C.; Wang, S.; Wen, W.; Yuan, J.; Cao, G.; Tian, J., Room-Temperature Construction of Mixed-Halide Perovskite Quantum Dots with High Photoluminescence Quantum Yield. J. Phys. Chem. C 2018, 122 (9), 5151-5160. 10. Wang, H.-C.; Wang, W.; Tang, A.-C.; Tsai, H.-Y.; Bao, Z.; Ihara, T.; Yarita, N.; Tahara, H.; Kanemitsu, Y.; Chen, S.; Liu, R.S., High-Performance Novel CsPb1-xSnxBr3 Perovskite Quantum Dots for Highly-Efficient Light-Emitting Diodes. Angew. Chem. Int. Edit. 2017, 56 (44), 13650-13654.


Page 6 of 9

Page 7 of 9 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

Chemistry of Materials 11. Wang, H. C.; Lin, S. Y.; Tang, A. C.; Singh, B. P.; Tong, H. C.; Chen, C. Y.; Lee, Y. C.; Tsai, T. L.; Liu, R. S., Mesoporous Silica Particle Integrated with All‐Inorganic CsPbBr3 Perovskite Quantum ‐Dot Nanocomposite (MP-PQDs) with High Stability and Wide Color Gamut Used for Backlight Display. Angew. Chem. Int. Edit. 2016, 55 (28), 7924-7929. 12. Xuan, T. T.; Yang, X.; Lou, S.; Huang, J.; Liu, Y.; Yu, J.; Li, H.; Wong, K. L.; Wang, C.; Wang, J., High Stable CsPbBr3 Quantum Dots Coated with Alkyl Phosphate for White LightEmitting Diodes. Nanoscale 2017, 9, 15286-15290. 13. Lou, S.; Xuan, T.; Yu, C.; Cao, M.; Xia, C.; Wang, J.; Li, H., Nanocomposites of CsPbBr3 Perovskite Nanocrystals in an Ammonium Bromide Framework with Enhanced Stability. J. Mater. Chem. C 2017, 5 (30), 7431-7435. 14. Lou, S.; Xuan, T.; Liang, Q.; Huang, J.; Cao, L.; Yu, C.; Cao, M.; Xia, C.; Wang, J.; Zhang, D.; Li, H., Controllable and facile synthesis of CsPbBr3-Cs4PbBr6 perovskite composites in pure polar solvent. J. Colloid Interface Sci. 2019, 537, 384-388. 15. Hou, S.; Guo, Y.; Tang, Y.; Quan, Q., Synthesis and Stabilization of Colloidal Perovskite Nanocrystals by Multidentate Polymer Micelles. ACS Appl. Mater. Interfaces 2017, 9 (22), 1841718422. 16. Lin, C. C.; Jiang, D.-H.; Kuo, C.-C.; Cho, C.-J.; Tsai, Y.H.; Satoh, T.; Su, C., Water-Resistant Efficient Stretchable Perovskite-Embedded Fiber Membranes for Light-Emitting Diodes. ACS Appl. Mater. Interfaces 2018, 10 (3), 2210-2215. 17. Li, Z.; Kong, L.; Huang, S.; Li, L., Highly Luminescent and Ultra-stable CsPbBr3 Pervoskite Quantum Dotssilica/alumina Monolith. Angew. Chem. Int. Edit. 2017, 56 (28), 8134–8138. 18. Luo, B.; Pu, Y.-C.; Lindley, S. A.; Yang, Y.; Lu, L.; Li, Y.; Li, X.; Zhang, J. Z., Organolead Halide Perovskite Nanocrystals: Branched Capping Ligands Control Crystal Size and Stability. Angew. Chem. Int. Edit. 2016, 55 (31), 8864-8868. 19. Nguyen, H. D.; Lin, C. C.; Liu, R. S., Waterproof Alkyl Phosphate Coated Fluoride Phosphors for Optoelectronic Materials. Angew. Chem. Int. Edit. 2015, 54 (37), 10862-10866. 20. Pan, A.; Wang, J.; Jurow, M. J.; Jia, M.; Liu, Y.; Wu, Y.; Zhang, Y.; He, L.; Liu, Y., A General Strategy for the Preparation of Stable Luminous Nanocomposite Inks Using Chemically Addressable CsPbX3 Peroskite Nanocrystals. Chem. Mater 2018, 30 (8), 2771-2780. 21. Woo, J. Y.; Kim, Y.; Bae, J.; Kim, T. G.; Kim, J. W.; Lee, D. C.; Jeong, S., Highly Stable Cesium Lead Halide Perovskite Nanocrystals through in Situ Lead Halide Inorganic Passivation. Chem. Mater 2017, 29 (17), 7088-7092. 22. Zhang, X.; Wang, H.-C.; Tang, A.-C.; Lin, S.-Y.; Tong, H.C.; Chen, C.-Y.; Lee, Y.-C.; Tsai, T.-L.; Liu, R.-S., Robust and Stable Narrow-Band Green Emitter: An Option for Advanced WideColor-Gamut Backlight Display. Chem. Mater. 2016, 28 (23), 84938497. 23. Xuan, T.; Lou, S.; Huang, J.; Cao, L.; Yang, X.; Li, H.; Wang, J., Monodisperse and brightly luminescent CsPbBr3/Cs4PbBr6 perovskite composite nanocrystals. Nanoscale 2018, 10, 9840-9844. 24. Sun, C.; Zhang, Y.; Ruan, C.; Yin, C.; Wang, X.; Wang, Y.; Yu, W. W., Efficient and Stable White LEDs with Silica‐Coated Inorganic Perovskite Quantum Dots. Adv. Mater. 2016, 28 (45), 10088-10094. 25. Wei, Y.; Xiao, H.; Xie, Z.; Liang, S.; Liang, S.; Cai, X.; Huang, S.; Kheraif, A. A. A.; Jang, H. S.; Cheng, Z.; Lin, J., Highly Luminescent Lead Halide Perovskite Quantum Dots in Hierarchical CaF2 Matrices with Enhanced Stability as Phosphors for White Light ‐ Emitting Diodes. Adv. Optical Mater. 2018, 6 (11), 1701343.

26. Raja, S. N.; Bekenstein, Y.; Koc, M. A.; Fischer, S.; Zhang, D.; Lin, L.; Ritchie, R. O.; Yang, P.; Alivisatos, A. P., Encapsulation of Perovskite Nanocrystals into Macroscale Polymer Matrices: Enhanced Stability and Polarization. ACS Appl. Mater. Interfaces 2016, 8 (51), 35523-35533. 27. Wei, Y.; Deng, X.; Xie, Z.; Cai, X.; Liang, S.; Ma, P. a.; Hou, Z.; Cheng, Z.; Lin, J., Enhancing the Stability of Perovskite Quantum Dots by Encapsulation in Crosslinked Polystyrene Beads via a Swelling–Shrinking Strategy toward Superior Water Resistance. Adv. Funct. Mater. 2017, 27 (39), 1703535. 28. Wang, S.; Liu, K.; Yao, X.; Jiang, L., Bioinspired surfaces with superwettability: new insight on theory, design, and applications. Chem. Rev. 2015, 115 (16), 8230-8293. 29. Feng, L.; Li, S.; Li, Y.; Li, H.; Zhang, L.; Zhai, J.; Song, Y.; Liu, B.; Jiang, L.; Zhu, D., Super ‐ hydrophobic surfaces: from natural to artificial. Adv. Mater. 2002, 14 (24), 1857-1860. 30. Wang, P.; Zhao, T.; Bian, R.; Wang, G.; Liu, H., Robust Superhydrophobic Carbon Nanotube Film with Lotus Leaf Mimetic Multiscale Hierarchical Structures. ACS Nano 2017, 11 (12), 12385-12391. 31. Yabu, H.; Shimomura, M., Single-step fabrication of transparent superhydrophobic porous polymer films. Chem. Mater. 2005, 17 (21), 5231-5234. 32. Tsougeni, K.; Vourdas, N.; Tserepi, A.; Gogolides, E.; Cardinaud, C., Mechanisms of oxygen plasma nanotexturing of organic polymer surfaces: from stable super hydrophilic to super hydrophobic surfaces. Langmuir 2009, 25 (19), 11748-11759. 33. Li, Y.; Zhang, Z.; Ge, B.; Men, X.; Xue, Q., One-pot, template-free synthesis of a robust superhydrophobic polymer monolith with an adjustable hierarchical porous structure. Green Chem. 2016, 18 (19), 5266-5272. 34. Protesescu, L.; Yakunin, S.; Bodnarchuk, M. I.; Krieg, F.; Caputo, R.; Hendon, C. H.; Yang, R. X.; Walsh, A.; Kovalenko, M. V., Nanocrystals of cesium lead halide perovskites (CsPbX3, X= Cl, Br, and I): novel optoelectronic materials showing bright emission with wide color gamut. Nano Lett. 2015, 15 (6), 3692-3696. 35. Sun, Q.; Aguila, B.; Verma, G.; Liu, X.; Dai, Z.; Deng, F.; Meng, X.; Xiao, F.-S.; Ma, S., Superhydrophobicity: constructing homogeneous catalysts into superhydrophobic porous frameworks to protect them from hydrolytic degradation. Chem 2016, 1 (4), 628-639. 36. Lum, K.; Chandler, D.; Weeks, J. D., Hydrophobicity at Small and Large Length Scales. J. Phys. Chem. B 1999, 103 (22), 4570-4577. 37. Chen, X.; Zhang, F.; Ge, Y.; Shi, L.; Huang, S.; Tang, J.; Lv, Z.; Zhang, L.; Zou, B.; Zhong, H., Centimeter-Sized Cs4PbBr6 Crystals with Embedded CsPbBr3 Nanocrystals Showing Superior Photoluminescence: Nonstoichiometry Induced Transformation and Light-Emitting Applications. Adv. Funct. Mater. 2018, 28 (16), 1706567. 38. Xin, Y.; Zhao, H.; Zhang, J., Highly Stable and Luminescent Perovskite–Polymer Composites from a Convenient and Universal Strategy. ACS Appl. Mater. Interfaces 2018, 10 (5), 4971-4980. 39. Loiudice, A.; Saris, S.; Oveisi, E.; Alexander, D. T. L.; Buonsanti, R., CsPbBr3 QD/AlOx Inorganic Nanocomposites with Exceptional Stability in Water, Light, and Heat. Angew. Chem. Int. Edit. 2017, 56 (36), 10696–10701. 40. Wang, C.; Chesman, A. S. R.; Jasieniak, J. J., Stabilizing the cubic perovskite phase of CsPbI3 nanocrystals by using an alkyl phosphinic acid. Chem. Commun. 2017, 53 (1), 232-235. 41. Pan, J.; Shang, Y.; Yin, J.; De Bastiani, M.; Peng, W.; Dursun, I.; Sinatra, L.; El-Zohry, A. M.; Hedhili, M. N.; Emwas, A.H.; Mohammed, O. F.; Ning, Z.; Bakr, O. M., Bidentate LigandPassivated CsPbI3 Perovskite Nanocrystals for Stable Near-Unity Photoluminescence Quantum Yield and Efficient Red LightEmitting Diodes. J. Am. Chem. Soc. 2018, 140 (2), 562-565.



42. Wei, Y.; Cheng, Z.; Lin, J., An overview on enhancing the stability of lead halide perovskite quantum dots and their

applications in phosphor-converted LEDs. Chem. Soc. Rev. 2019, 48, 310-350.


Page 8 of 9

Page 9 of 9 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


For Table of Contents Only


Super-Hydrophobic Cesium Lead Halide Perovskite Quantum Dot

Recommend Documents