ALD Preparation Of Inorganic Conductive Oxide Transport Layer For Perovskite LED

Metal halide perovskites have been widely studied in the semiconductor field for their excellent electrical and optical properties,including high photoluminescence quantum yield（PLQY）,wide adjustable band gap,high luminous color purity and excellent charge carrier mobility.Its applications include photovoltaic,laser,light emitting diode,detector and memory resistors,etc.In recent years,they have made rapid development in the field of optoelectronic devices and have been proved to be promising candidate materials for the preparation of light-emitting diode（LED）.However,they still face the bottleneck of low efficiency and poor stability.The aim of this thesis is to optimize the composition of the light-emitting layer of the device,select the appropriate inorganic transport layer and adjust the organic transport layer,improve the film morphology and carriers balance,and the crystal quality to prepare devices with reliable performance and good stability.The main research work of this thesis is as follows:1.By adding polyethylene（PEO）and polyethylene pyrrolidone（PVP）into the precursor solution,the compactness and crystallinity of Cs Pb Br₃ all-inorganic perovskite film were improved.Then,the luminescence performance and stability of perovskite LED were improved by growing alumina of different thickness in ALD as charge transport layer.The results show that the addition of PEO and PVP can effectively reduce the carrier leakage current caused by the pinhole.Based on these studies,I prepared inorganic transport layer alumina halide perovskite green LED with high brightness and stability.2.The densification and crystallinity of Cs Pb(Br _XCl_1-X)₃ inorganic perovskite films were improved by adding polyethylene glycol（PEG）and phenythylamine bromide（PEABr）into the precursor solution.The results show that adding PEG into the precursor solution can improve the morphology of perovskite film and reduce the leakage current of LED.By adding a certain amount of magnesium acetate tetrahydrate（Mg（CH₃COOH）₂·4H₂O）in the hole transport layer PEDOT:PSS（4083）can adjust band gap of the layer,adjust the band gap matching degree,improve the mobility of holes,and promote the balance of carriers transport.Meanwhile,hydrophobicity of magnesium acetate tetrahydrate can adjust the grain growth orientation,making the perovskite light emitting layer film more conducive to the fabrication of devices.Based on these,this paper prepared perovskite blue LED with high brightness and stability.