Preparation And Properties Of The CIAS And CH₃NH₃PbI₃ Absorber Layers For The Thin Film Solar Cells

In recent years, environmental pollution and energy crisis problems have become more serious and greatly promoted the development of photovoltaic industry. Solar energy as one of the most potential renewable resources can effectively solve these two problems. Photovoltaic is one of the important ways of utilizing solar energy. Solar cell is a device that converts light energy into electrical energy by photovoltaic effect. Chalcopyrite structure CuInSe2 (CIS) semiconductor solar cell and perovskite structure CH3NH3PbI3 solar cell with its excellent photoelectric conversion properties and various processing advantages get international attention.Two research contents in this thesis:by doping Al element to replace part of In, preparation of CIAS film as the absorption layer of CIAS thin film solar cell, reduce cost and reduce oxygen.CH3NH3PbI3 thin films were prepared by soaking assisted evaporation two-step method and spin-coating method. Focusing on the influence of soaking time and spin-coating speed on the structure and properties of CH3NH3PbI3 thin films. Respectively using X-ray diffraction, scanning electron microscope and EDS energy spectrometer, profiler, Holzer effect instrument, ultraviolet visible near infrared spectrophotometer in CIAS and CH3NH3PbI3 thin film structure, morphology, composition, thickness and photoelectric properties were studied.The results show that CIAS thin film prepared by metal precursor film selenide (annealing temperature was 500℃) is showing a chalcopyrite crystal structure, and with the (112) crystal face preferred growth. Partial substitution of Al for CIS in the lattice of In. CIAS thin film conductivity type is P type, the carrier concentration up to 1021 orders of magnitude. But in the long time annealing process, In and Al was evaporated, which leads to the imbalance of chemical equivalent. The electrical properties of the films containing Cu-Se compounds are not suitable for solar cell absorption. It is suggested that the thin film is annealed by rapidly thermal processing to solve this problem. CH3NH3PbI3 thin film prepared by two-step method reacted incompletely. CH3NH3PbI3 thin film prepared by spin-coating are very complete, showing a perovskite crystal structure. But there is a problem that the film coverage is not good. In the future production of solar cell devices, the CH3NH3PbI3 spin-coating on the compact oxide film will improve the coverage of CH3NH3PbI3. CH3NH3PbI3 thin film prepared by one-step spin-coating method is more suitable for the absorption layer of CH3NH3PbI3 thin film solar cell.