The Interface Modification And Energy Band Engineering For Organic-inorganic Hybrid Film Solar Cell

Inorganic-organic metal halide perovskite material is increasingly being investigated by scientific researchers and is an outstanding candidate for the next generation of solar cells,because it has excellent photo-voltaic performance,such as adjustable band gaps,bidirectional charge transport,a longer exciton transport distances,high absorption coefficients and carrier mobility.The PCE of the devices has been rapidly developed in recent years and the fabrication process of the devices is also optimized.So far,the highest PCE has reached 22%.However,the metal halide perovskite material contains toxic elements,which pollutes the environment.In addition,the traditional devices still have hysteresis phenomenon and display instability in environmental which are unfavorable for scale production and commercial application.According to the previous reports,some efforts have been made to alleviate these negative effects and improve performance.In this paper,perovskite solar cells with high-performance were prepared via modification perovskite material and electronic or hole interface.?1?The morphology and grain size of the perovskite film are improved and the performance of the device is greatly improved by adding ammonium hypophosphite?AHP?to the perovskite material.The effects of different AHP concentrations on the grain size and the films morphology were investigated.The result has shown that the AHP plays an intermediate role for increasing the grain size,reducing the total grain boundary and the density of defect states.?2?The hysteresis phenomenon is completely eliminated by introducing an interfacial modification layer between the perovskite layer and the ETL TiO₂.The interface with hydrophobic also promotes the growth of the perovskite film and the PCE of the devices.The stability of the interfacial layers at different concentrations was studied.The experimental results shown the devices based on this interface modification layer have a good performance and negligible hysteresis.?3?The modification of the perovskite layer and the electron transport layer of the PEDOT:PSS-based invert devices have resulted in a significant increase in the fill factor and voltage.It was studied that the effect of different precursor concentration during the preparation of standard devices and the change of device performance after adding AHP.Finally,the influence of the interface modified layer for the device performance was studied.The results show that the performance of inverting the device has been greatly improved by this method.