Designd And Properties Of Perovskitesolar Cells Through Controlling Synergistic Absorbing And Interface Layers

Inorganic-organic hybrid perovskite solar cells?PSCs?have demonstrated high power conversion efficiencies?PCEs?of over 24%and attracted wide attention due to low-cost solution processing methods.Perovskite materials have extraordinary and unique optoelectronic properties due to their adjustable bandgap,high extinction coefficient,long carrier diffusion length and high mobility.In addition,the PCEs of PSCs are very close to those of crystalline-silicon solar cells as well as other inorganic thin-film solar cells.These advantages make them an ideal candidate for high-efficiency and low-cost alternative photovoltaics.For PSCs,a perovskite layer is sandwiched between a hole extraction layer and an electron extraction layer.The quality of the perovskite layer plays a vital role in device performance,which not only ensures sufficient light harvesting,but also reduces charge recombination and improves charge transport,thereby improving photovoltaic performance.In addition,interface materials have a significant impact on device performance,and the materials with matched energy levels and high mobility can effectively promote charge extraction and transport to further improve device efficiency.However,the preparation of high-quality perovskite films and excellent interface transport materials are still very challenging.In this study,the morphology of perovskite film was effectively controlled by additive engineering,and the high-quality perovskite film was explored in different device structures.Furthermore,the effects of different interface materials on power conversion efficiency and stability of the device were studied.The detailed work is as follows:1.The film quality of the perovskite layer is regulated by additive engineering.A new type of perovskite additive-FAAc,was introduced into the precursor,which can obtain a dense,crack-free perovskite layer by regulating the crystallization and growth of the perovskite phase.The fully covered perovskite film can effectively improve photovoltaic performance and stability of perovskite solar cells.The power conversion efficiency of the inverted planar perovskite solar cells with hole transport layer material?PEDOT:PSS?increased from initial 12.30%to 16.59%,and the fill factor of the device was significantly improved with the maximum value of 81%.Furthermore,there is no hysteresis.At the same time,the stability of the device was also significantly improved as the PCE maintains 90%after being placed in glove box for30 days without any encapsulation.2.Interface materials with matched energy levels and high transmission can improve the efficiency and stability of the device.Furthermore,it can verify the universality of high-quality perovskite films prepared by additive engineering.Here,poly[bis?4-phenyl??2,4,6-trimethylphenyl?]amine?PTAA?was used to replace traditional PEDOT:PSS.The PCE was increased from 16.59%to 18.90%,and all three parameters were significantly improved.Moreover,the stability of the device was improved.The device fabricated under the same conditions can maintain 90%after 80days.The method provides a good experimental design idea for preparing high-efficiency and stable PSCs.3.There are mainly two types of device configurations for planar PSC:conventional and inverted structures.A high-quality tin oxide?SnO₂?nanofilm was prepared by a low temperature solution process for conventional planar PSCs.Due to wide band gap of SnO₂ and low surface roughness and excellent transmission of FTO film,the optimized solar cell device achieved 18.47%and 18.15%of the PCE under reverse and forward voltage scanning,respectively.There was no hysteresis and the stability of the device was further improved.This method not only promotes rapid development of low-cost and high-efficiency conventional planar PSCs,but also provides an opportunity for low-temperature processes and roll-to-roll preparation of large-scale PSCs on flexible substrates.