Application and Development of Cesium Lead Halide Perovskite Based Planar Heterojunction LEDs

doi:10.15541/jim20180176

Abstract

Abstract:

All-inorganic cesium lead halide CsPbX₃ (X = Cl, Br, I) perovskite materials emerged as a rising star in the area of optoelectronics since 2015, due to its excellent photoelectric properties and environmental stability. Substantial progresses were made in the application of many electronic and optoelectronic devices, which attracted wide attention from the scientific community. This paper mainly reviews the latest research progress of cesium lead halide perovskite based planar heterojunction LED, where the structure and working principle of LED devices are briefly introduced. In addition, the classification and summarization of some optimization strategies for improving luminescence performance and working stability of LED devices are emphatically suggested, and the development trend of stable and efficient inorganic perovskite based planar heterojunction LED is finally prospected.

Key words: cesium lead halide perovskite, planar heterojunction, LED, stability, doping, review

CLC Number:

O472

ZHANG Lou-Wen, SHEN Shao-Li, LI Lu-Ying, ZHANG Zhi, LIU Ni-Shuang, GAO Yi-Hua. Application and Development of Cesium Lead Halide Perovskite Based Planar Heterojunction LEDs[J]. Journal of Inorganic Materials, 2019, 34(1): 37-48.

Figures/Tables 9

Fig. 1 Optimization strategies for luminescence performance and stability of LED devices

Fig. 2 Schematic diagram of the device structures (a, b) and working mechanism (c) for perovskite based planar heterojunction LEDs

Fig. 3 (a) Schematic diagram of device structure; (b) Cross-sectional TEM image. Scale bar, 50 nm; (c) Flat-band energy level diagram; (d) The EL spectra (straight line) of devices for CsPb(Cl/Br)3, CsPbBr3 and CsPb(Br/I)3 under applied voltage of 5.5 V, and the photoluminescence (PL) spectra (dashed line) of QDs dispersed in hexane[58]

Fig. 4 (a) Schematic illustration of device structure and a cross-sectional TEM image (scale bar: 50 nm); (b) Normalized EL spectra (solid lines) and PL spectra (dashed lines) of CsPbBr3 QLEDs with two purifying cycles. Inset in (b): The photograph of a working device at an applied voltage of 5 V; (c) EQE of these devices for QDs with different purifying cycles as a function of luminance[59]

Fig. 5 (a) Structural representation of CsPbBr3 based LEDs; (b) Current efficiency-voltage (CE-V), and EQE-voltage (EQE-V) characteristic curves[68]; The surface morphology of CsPbBr3 film and surface luminous photo of LED (c) without treatment and (d) with chlorobenzene treatment[69]

Fig. 6 (a) EQE and CE as a function of voltage among devices fabricated with different ETL and HTL materials[77]; (b) EQE-V curves for the LEDs with different PEG:CsPbBr3 (CsBr:PbBr2 molar ratio of 1.4:1) weight ratios[78]; (c) TEM image of cross section of device and corresponding schematic diagram of device structure; (d) EQE for the devices with and without Ag rod[79]

Fig. 7 (a) Overall energy band diagram of the LED structure; (b) EQE and CE vs current density of devices with or without PFI interface modifier[85]; (c) Schematic diagram of device structure; (d) CE and EQE of devices with and without PVP buffer layer, with and without CH3NH3Br (MABr) additive[51]

Fig. 8 (a) Schematic illustration of device structure; (b) EQE of the devices as a function of luminance[90]; (c) Band alignment of each functional layer; (d) EQE of the devices as a function of driving voltage[91]

Fig. 9 (a) Simplified energy band alignment of the LED; (b) Luminous efficiency and EQE versus voltage of the LED[99]; (c) Schematic illustration of solution-processed perovskite LED; (d) EQE, CE, and power efficiency versus voltage of the LED[102]

References 102

[1]	KOJIMA A, TESHIMA K, SHIRAI Y, et al.Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. Journal of the American Chemical Society, 2009, 131(17): 6050-6051.
[2]	IM J H, LEE C R, LEE J W, et al.6.5% efficient perovskite quantum-dot-sensitized solar cell. Nanoscale, 2011, 3(10): 4088-4093.
[3]	LEE M M, TEUSCHER J, MIYASAKA T, et al.Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science, 2012, 338(6107): 643-647.
[4]	BURSCHKA J, PELLET N, MOON S, et al.Sequential deposition as a route to high-performance perovskite-sensitized solar cells. Nature, 2013, 499(7458): 316-319.
[5]	LIU M, JOHNSTON M B, SNAITH H J.Efficient planar heterojunction perovskite solar cells by vapour deposition. Nature, 2013, 501(7467): 395-398.
[6]	GRÄTZEL M. The light and shade of perovskite solar cells. Nat. Mater., 2014, 13(9): 838-842.
[7]	ZHOU H, CHEN Q, LI G, et al.Interface engineering of highly efficient perovskite solar cells. Science, 2014, 345(6196): 542-546.
[8]	NIE W, TSAI H, ASADPOUR R, et al.High-efficiency solution- processed perovskite solar cells with millimeter-scale grains. Science, 2015, 347(6221): 522-525.
[9]	YANG W S, NOH J H, JEON N J, et al.High-performance photovoltaic perovskite layers fabricated through intramolecular exchange. Science, 2015, 348(6240): 1234-1237.
[10]	YANG W S, PARK B W, JUNG E H, et al.Iodide management in formamidinium-lead-halide-based perovskite layers for efficient solar cells. Science, 2017, 356(6345): 1376-1379.
[11]	VELDHUIS S A, BOIX P P, YANTARA N, et al.Perovskite materials for light-emitting diodes and lasers. Advanced Materials, 2016, 28(32): 6804-6834.
[12]	TAN Z K, MOGHADDAM R S, LAI M L, et al.Bright light-emitting diodes based on organometal halide perovskite. Nature Nanotechnology, 2014, 9: 687-692.
[13]	LI G, TAN Z K, DI D, et al.Efficient light-emitting diodes based on nanocrystalline perovskite in a dielectric polymer matrix. Nano Letters, 2015, 15: 2640-2644.
[14]	JARAMILLOQUINTERO O A, SANCHEZ R S, RINCON M, et al.Bright visible-infrared light emitting diodes based on hybrid halide perovskite with spiro-OMeTAD as a hole-injecting layer. Journal of Physical Chemistry Letters, 2015, 6: 1883-1890.
[15]	XING J, YAN F, ZHAO Y, et al.High-efficiency light-emitting diodes of organometal halide perovskite amorphous nanoparticles. ACS Nano, 2016, 10: 6623-6630.
[16]	WANG J, WANG N, JIN Y, et al.Interfacial control toward efficient and low-voltage perovskite light-emitting diodes. Advanced Materials, 2015, 27(16): 2311-2316.
[17]	CHO H, JEONG S H, PARK M H, et al.Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes. Science, 2015, 350(6265): 1222-1225.
[18]	DOU L, WONG A B, YU Y, et al.Atomically thin two-dimensional organic-inorganic hybrid perovskites. Science, 2015, 349(6255): 1518-1521.
[19]	SADHANALA A, AHMAD S, ZHAO B, et al.Blue-green color tunable solution processable organolead chloride-bromide mixed halide perovskites for optoelectronic applications. Nano Letters, 2015, 15: 6095-6101.
[20]	KIM Y H, CHO H, HEO J H, et al.Multicolored organic/inorganic hybrid perovskite light-emitting diodes. Advanced Materials, 2015, 27(7): 1248-1254.
[21]	HOYE R L Z, CHUA M R, MUSSELMAN K P, et al. Enhanced performance in fluorene-free organometal halide perovskite light-emitting diodes using tunable, low electron affinity oxide electron injectors. Advanced Materials, 2015, 27(8): 1414-1419.
[22]	YU J C, KIM D B, BAEK G, et al.High-performance planar perovskite optoelectronic devices: a morphological and interfacial control by polar solvent treatment. Advanced Materials, 2015, 27(23): 3492-3500.
[23]	YUAN M, QUAN L N, COMIN R, et al.Perovskite energy funnels for efficient light-emitting diodes. Nature Nanotechnology, 2016, 11(10): 872-877.
[24]	WANG N, CHENG L, GE R, et al.Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells. Nature Photonics, 2016, 10: 699-704.
[25]	XIAO Z, KERNER R A, ZHAO L, et al.Efficient perovskite light-emitting diodes featuring nanometre-sized crystallites. Nature Photonics, 2017, 11: 108-115.
[26]	LIAO Q, HU K, ZHANG H, et al.Perovskite microdisk microlasers self-assembled from solution. Advanced Materials, 2015, 27(22): 3405-3410.
[27]	SALIBA M, WOOD S M, PATEL J B, et al.Structured organic- inorganic perovskite toward a distributed feedback laser. Advanced Materials, 2016, 28(5): 923-929.
[28]	AHMADI M, WU T, HU B. A review on organic-inorganic halide perovskite photodetectors: device engineering and fundamental physics. Advanced Materials, 2017, 29(41): 1605242-1-24.
[29]	DONG R, FANG Y, CHAE J, et al.High-gain and low-driving- voltage photodetectors based on organolead triiodide perovskites. Advanced Materials, 2015, 27(11): 1912-1918.
[30]	LIN Q, ARMIN A, BURN P L, et al.Filterless narrowband visible photodetectors. Nature Photonics, 2015, 9(10): 687-694.
[31]	CHEN H W, SAKAI N, JENA A K, et al.A switchable high-sensitivity photodetecting and photovoltaic device with perovskite absorber. Journal of Physical Chemistry Letters, 2015, 6(9): 1773-1779.
[32]	SAIDAMINOV M I, VALERIO A, RICCARDO C, et al. Planar- integrated single-crystalline perovskite photodetectors. Nature Communication, 2015, 6: 8724-1-7.
[33]	MACULAN G, SHEIKH A D, ABDELHADY A L, et al.CH3NH3PbCl3 single crystals: inverse temperature crystallization and visible-blind UV-photodetector. Journal of Physical Chemistry Letters, 2015, 6(19): 3781-3786.
[34]	YAN K, PENG M, YU X, et al.High-performance perovskite memristor based on methyl ammonium lead halides. Journal of Materials Chemistry C, 2016, 4(7): 1375-1381.
[35]	GU C, LEE J S.Flexible hybrid organic-inorganic perovskite memory. ACS Nano, 2016, 10(5): 5413-5418.
[36]	KULBAK M, GUPTA S, KEDEM N, et al.Cesium enhances long-term stability of lead bromide perovskite-based solar cells. Journal of Physical Chemistry Letters, 2016, 7(1): 167-172.
[37]	KULBAK M, CAHEN D, HODES G.How important is the organic part of lead halide perovskite photovoltaic cells? efficient CsPbBr3 cells. Journal of Physical Chemistry Letters, 2015, 6(13): 2452-2456.
[38]	PROTESESCU L, YAKUNIN S, BODNARCHUK M I, et al.Nanocrystals of cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I): novel optoelectronic materials showing bright emission with wide color gamut. Nano Letters, 2015, 15(6): 3692-3696.
[39]	WU Y, WEI Y, HUANG Y, et al.Capping CsPbBr3 with ZnO to improve performance and stability of perovskite memristors. Nano Research, 2017, 10(5): 1584-1594.
[40]	LIU D, LIN Q, ZANG Z, et al.Flexible all-inorganic perovskite CsPbBr3 nonvolatile memory device. ACS Applied Materials & Interfaces, 2017, 9: 6171-6176.
[41]	HUO C, LIU X, SONG X, et al.Field-effect transistors based on Van-Der-Waals-grown and dry-transferred all-inorganic perovskite ultrathin platelets. Journal of Physical Chemistry Letters, 2017, 8: 4785-4792.
[42]	CHANG X, LI W, ZHU L, et al.Carbon-based CsPbBr3 perovskite solar cells: all-ambient processes and high thermal stability. ACS Applied Materials & Interfaces, 2016, 8: 33649-33655.
[43]	PANIGRAHI S, JANA S, CALMEIRO T, et al.Imaging the anomalous charge distribution inside CsPbBr3 perovskite quantum dots sensitized solar cells. ACS Nano, 2017, 11: 10214-10221.
[44]	CHEN C, LIN H, CHIANG K, et al. All-vacuum-deposited stoichiometrically balanced inorganic cesium lead halide perovskite solar cells with stabilized efficiency exceeding 11%. Advanced Materials, 2017, 29(12): 1605290-1-7.
[45]	ZENG Q S, ZHANG X Y, FENG X L, et al. Polymer-passivated inorganic cesium lead mixed-halide perovskites for stable and efficient solar cells with high open-circuit voltage over 1.3 V. Advanced Materials, 2018, 30(9): 1705393-1-9.
[46]	LI X, YU D, CHEN J, et al.Constructing fast carrier tracks into flexible perovskite photodetectors to greatly improve responsivity. ACS Nano, 2017, 11(2): 2015-2023.
[47]	XUE J, GU Y, SHAN Q, et al.Constructing Mie-scattering porous interface-fused perovskite films to synergistically boost light harvesting and carrier transport. Angewandte Chemie International Edition, 2017, 56(19): 5232-5236.
[48]	YANG B, ZHANG F, CHEN J, et al. Ultrasensitive and fast all-inorganic perovskite-based photodetector via fast carrier diffusion. Advanced Materials, 2017, 29(40): 1703758-1-8.
[49]	YANG T, ZHENG Y, DU Z, et al.Superior photodetectors based on all-inorganic perovskite CsPbI3 nanorods with ultrafast response and high stability. ACS Nano, 2018, 12(2): 1611-1617.
[50]	HUANG C Y, ZOU C, MAO C, et al.CsPbBr3 perovskite quantum dot vertical cavity lasers with low threshold and high stability. ACS Photonics, 2017, 4(9): 2281-2289.
[51]	ZHANG L, YANG X, JIANG Q, et al.Ultra-bright and highly efficient inorganic based perovskite light-emitting diodes. Nature Communication, 2017, 8: 15640.
[52]	CHO H, KIM Y H, WOLF C, et al. Improving the stability of metal halide perovskite materials and light-emitting diodes. Advanced Materials, 2018: 1704587-1-24.
[53]	LI X, CAO F, YU D, et al. All inorganic halide perovskites nanosystem: synthesis, structural features, optical properties and optoelectronic applications. Small, 2017, 13(9): 1603996-1-24.
[54]	HE X, QIU Y, YANG S. Fully-inorganic trihalide perovskite nanocrystals: a new research frontier of optoelectronic materials. Advanced Materials, 2017, 29(32): 1700775-1-27.
[55]	LI J, SHAN X, BADE S G R, et al. Single-layer halide perovskite light-emitting diodes with sub-band gap turn-on voltage and high brightness. Journal of Physical Chemistry Letters, 2016, 7(20): 4059-4066.
[56]	LY K T, CHENCHENG R W, LIN H W, et al.Near-infrared organic light-emitting diodes with very high external quantum efficiency and radiance. Nature Photonics, 2017, 11: 63-68.
[57]	SHIRASAKI Y, SUPRAN G J, BAWENDI M G, et al.Emergence of colloidal quantum-dot light-emitting technologies. Nature Photonics, 2013, 7(1): 13-23.
[58]	SONG J, LI J, LI X, et al.Quantum dot light-emitting diodes based on inorganic perovskite cesium lead halides (CsPbX3). Advanced Materials, 2015, 27(44): 7162-7167.
[59]	LI J, XU L, WANG T, et al. 50-fold EQE improvement up to 6.27% of solution-processed all-inorganic perovskite CsPbBr3 QLEDs via surface ligand density control. Advanced Materials, 2017, 29(5): 1603885-1-9.
[60]	PAN J, QUAN L N, ZHAO Y, et al.Highly efficient perovskite- quantum-dot light-emitting diodes by surface engineering. Advanced Materials, 2016, 28(39): 8718-8725.
[61]	TAN Y, ZOU Y, WU L, et al.Highly luminescent and stable perovskite nanocrystals with octylphosphonic acid as ligand for efficient light emitting diodes. ACS Applied Materials & Interfaces, 2018, 10(4): 3784-3792.
[62]	QIN C, MATSUSHIMA T, SANDANAYAKA A S D, et al. Centrifugal-coated quasi-two-dimensional perovskite CsPb2Br5 films for efficient and stable light-emitting diodes. Journal of Physical Chemistry Letters, 2017, 47(21): 5415-5421.
[63]	CHIBA T, HOSHI K, PU Y J, et al.High-efficiency perovskite quantum-dot light-emitting devices by effective washing process and interfacial energy level alignment. ACS Applied Materials & Interfaces, 2017, 9: 18054-18060.
[64]	ZOU C, HUANG C Y, SANEHIRA E M, et al. Highly stable cesium lead iodide perovskite quantum dot light-emitting diodes. Nanotechnology, 2017, 28(45): 455201-1-7.
[65]	XU J, HUANG W, LI P, et al. Imbedded nanocrystals of CsPbBr3 in Cs4PbBr6: kinetics, enhanced oscillator strength,application in light-emitting diodes. Advanced Materials, 2017, 29(43): 1703703-1-10.
[66]	LE Q V, PARK M, SOHN W, et al.Investigation of energy levels and crystal structures of cesium lead halides and their application in full-color light-emitting diodes. Advanced Electronic Materials, 2017, 3(1): 1600448.
[67]	SUH Y H, KIM T, CHOI J W, et al.High-performance CsPbX3 perovskite quantum dot light emitting devices via solid-state ligand exchange. ACS Applied Nano Materials, 2018, 1(2): 488-496.
[68]	WANG Z, LUO Z, ZHAO C, et al.Efficient and stable pure green all-inorganic perovskite CsPbBr3 light-emitting diodes with a solution-processed NiOx interlayer. Journal of Physical Chemistry C, 2017, 121: 28132-28138.
[69]	ZHANG X, WANG W, XU B, et al.Thin film perovskite light-emitting diode based on CsPbBr3, powders and interfacial engineering. Nano Energy, 2017, 37: 40-45.
[70]	HU Y, WANG Q, SHI Y L, et al.Vacuum-evaporated all-inorganic cesium lead bromine perovskites for high-performance light-emitting diodes. Journal of Materials Chemistry C, 2017, 5(32): 8144-8149.
[71]	CHO H, WOLF C, KIM J S, et al. High-efficiency solution- processed inorganic metal halide perovskite light-emitting diodes. Advanced Materials, 2017, 29(31): 1700579-1-8.
[72]	YANTARA N, BHAUMIK S, YAN F, et al.Inorganic halide perovskites for efficient light-emitting diodes. Journal of Physical Chemistry Letters, 2015, 6(21): 4360-4364.
[73]	YAN F N, WEI J N, JAMALUDIN N F, et al.Enhanced coverage of all-inorganic perovskite CsPbBr3 through sequential deposition for green light-emitting diodes. Energy Technology, 2017, 5: 1859-1865.
[74]	YAO E P, YANG Z, MENG L, et al. High-brightness blue and white LEDs based on inorganic perovskite nanocrystals and their composites. Advanced Materials, 2017, 29(23): 1606859-1-7.
[75]	NG Y F, JAMALUDIN N F, YANTARA N, et al.Rapid crystallization of all-inorganic CsPbBr3 perovskite for high-brightness light-emitting diodes. ACS Omega, 2017, 2(6): 2757-2764.
[76]	JIN F, ZHAO B, CHU B, et al.Morphology control towards bright and stable inorganic halide perovskite light-emitting diodes. Journal of Materials Chemistry C, 2018, 6: 1573-1578.
[77]	LING Y, TIAN Y, WANG X, et al.Enhanced optical and electrical properties of polymer-assisted all-inorganic perovskites for light-emitting diodes. Advanced Materials, 2016, 28: 8983-8989.
[78]	SONG L, GUO X, HU Y, et al.Efficient inorganic perovskite light-emitting diodes with polyethylene glycol passivated ultrathin CsPbBr3 films. Journal of Physical Chemistry Letters, 2017, 8: 4148-4154.
[79]	ZHANG X, XU B, WANG W, et al.Plasmonic perovskite light-emitting diodes based on Ag-CsPbBr3 system. ACS Applied Materials & Interfaces, 2017, 9(5): 4926-4931.
[80]	YU J C, LEE A Y, KIM D B, et al.Enhancing the performance and stability of perovskite nanocrystal light-emitting diodes with a polymer matrix. Advanced Materials Technologies, 2017, 2(6): 1700003.
[81]	YU F X, ZHANG Y, XIONG Z Y, et al.Full coverage all-inorganic cesium lead halide perovskite film for high-efficiency light-emitting diodes assisted by 1,3,5-tri(m-pyrid-3-yl-phenyl) benzene. Organic Electronics, 2017, 50: 480-484.
[82]	WU C, ZOU Y, WU T, et al. Improved performance and stability of all-inorganic perovskite light-emitting diodes by antisolvent vapor treatment. Advanced Functional Materials, 2017, 27(28): 1700338-1-7.
[83]	NG Y F, KULKARNI S A, PARIDA S, et al.Highly efficient Cs-based perovskite light-emitting diodes enabled by energy funnelling. Chemical Communications, 2017, 53(88): 12004-12007.
[84]	ZHANG X, XU B, ZHANG J, et al.All-inorganic perovskite nanocrystals for high-efficiency light emitting diodes: dual-phase CsPbBr3-CsPb2Br5 composites. Advanced Functional Materials, 2016, 26: 4595-4600.
[85]	ZHANG X, LIN H, HUANG H, et al.Enhancing the brightness of cesium lead halide perovskite nanocrystal based green light-emitting devices through the interface engineering with perfluorinated lonomer. Nano Letters, 2016, 16(2): 1415-1420.
[86]	ZHANG X, CAO W, WANG W, et al.Efficient light-emitting diodes based on green perovskite nanocrystals with mixed-metal cations. Nano Energy, 2016, 30: 511-516.
[87]	MIR W J, JAGADEESWARARAO M, DAS S, et al.Colloidal Mn-doped cesium lead halide perovskite nanoplatelets. ACS Energy Letters, 2017, 2: 537-543.
[88]	SHAI X, ZUO L, SUN P, et al.Efficient planar perovskite solar cells using halide Sr-substituted Pb perovskite. Nano Energy, 2017, 36: 213-222.
[89]	BEGUM R, PARIDA M R, ABDELHADY A L, et al.Engineering interfacial charge transfer in CsPbBr3 perovskite nanocrystals by heterovalent doping. Journal of the American Chemical Society, 2017, 139: 731-737.
[90]	ZOU S, LIU Y, LI J, et al.Stabilizing cesium lead halide perovskite lattice through Mn(II) substitution for air-stable light-emitting diodes. Journal of the American Chemical Society, 2017, 139: 11443-11450.
[91]	YAO J, GE J, HAN B N, et al.Ce3+-doping to modulate photoluminescence kinetics for efficient CsPbBr3 nanocrystals based light-emitting diodes. Journal of the American Chemical Society, 2018, 140(10): 3626-3634.
[92]	JELLICOE T C, RICHTER J M, GLASS H F J, et al. Synthesis and optical properties of lead-free cesium tin halide perovskite nanocrystals. Journal of the American Chemical Society, 2016, 138(9): 2941-2944.
[93]	CHEN L J, LEE C R, CHUANG Y J, et al.Synthesis and optical properties of lead-free cesium tin halide perovskite quantum rods with high-performance solar cell application. Journal of Physical Chemistry Letters, 2016, 7: 5028-5035.
[94]	YANG B, CHEN J, HONG F, et al.Lead-free, air-stable all-inorganic cesium bismuth halide perovskite nanocrystals. Angewandte Chemie International Edition, 2017, 56: 12471-12475.
[95]	TONG X, KONG W, WANG Y, et al.High-performance red light photodetector based on lead-free bismuth halide perovskite film. ACS Applied Materials & Interfaces, 2017, 9(22): 18977-18985.
[96]	WANG A, GUO Y, MUHAMMAD F, et al.Controlled synthesis of lead-free cesium tin halide perovskite cubic nanocages with high stability. Chemistry of Materials, 2017, 29: 6493-6501.
[97]	ZHANG J, YANG Y, DENG H, et al.High quantum yield blue emission from lead-free inorganic antimony halide perovskite colloidal quantum dots. ACS Nano, 2017, 11: 9294-9302.
[98]	LENG M, YANG Y, ZENG K, et al. All-inorganic bismuth-based perovskite quantum dots with bright blue photoluminescence and excellent stability. Advanced Functional Materials, 2018, 28: 1704446-1-11.
[99]	SHI Z, LI Y, ZHANG Y, et al.High-efficiency and air-stable perovskite quantum dots light-emitting diodes with an all-inorganic heterostructure. Nano Letters, 2016, 17(1): 313-321.
[100]	SHAN Q, LI J, SONG J, et al.All-inorganic quantum-dot light-emitting diodes based on perovskite emitters with low turn-on voltage and high humidity stability. Journal of Materials Chemistry C, 2017, 5(18): 4565-4570.
[101]	ZHUANG S, MA X, HU D, et al.Air-stable all inorganic green perovskite light emitting diodes based on ZnO/CsPbBr3/NiO heterojunction structure. Ceramics International, 2018, 44(5): 4685-4688.
[102]	SHI Z, LI S, LI Y, et al.Strategy of solution-processed all-inorganic heterostructure for humidity/temperature-stable perovskite quantum dot light-emitting diodes. ACS Nano, 2018, 12(2): 1462-1472.