Advanced materials: new progress in research on two-dimensional perovskite solar cells

The two-dimensional ruddlesden Popper (RP) hybrid perovskite semiconductor has been widely concerned by researchers in this field because of its excellent stability and photoelectric performance Under the guidance of Liu Shengzhong, researcher of thin film silicon solar cell research group (dnl1606), Zhao Kui, associate professor of Shaanxi Normal University, and Aram amassian, associate professor of King Abdullah University, Saudi Arabia, Zhang Xu, Ph.D., graduate student of Dalian Institute of chemistry, Chinese Academy of Sciences, etc., made new progress in the research of two-dimensional perovskite crystallization kinetics Relevant research results were published in advanced materials Above (DOI: 10.1002/adma.201707166) In this study, the effects of substrate temperature and solvent properties on the two-dimensional perovskite crystallization kinetics, film phase purity, quantum well alignment and photovoltaic performance were studied by using high-energy synchrotron radiation technology and tracking the phase transition behavior in the process of solid-state film formed by the reaction of two-dimensional perovskite precursor solution in real time The researchers found that the decrease of the purity of two-dimensional perovskite phase and the order of crystal orientation is mainly due to the increase of the nuclear energy barrier of perovskite when the intermediate state of "precursor solvent" was formed Therefore, the nucleation and growth of two-dimensional perovskite induced by the substrate is the key to the formation of high-quality perovskite films Through the substrate induced crystallization, the researchers suppressed the formation of the "drive solvent" intermediate state, which led to the vertical orientation of the two-dimensional quantum well, making it more stable in thermodynamics, and further improving the crystal phase purity As high quality perovskite films can greatly improve the photoelectric conversion efficiency of solar cells, this study provides a theoretical basis for the preparation of high-quality low-dimensional perovskite films and high-performance photoelectric devices, which will help promote the further commercial application of perovskite solar cells The above research work was supported by the national key research and development plan, the National Natural Science Foundation, the central university fund, the "111 talent introduction plan" of the Ministry of education, the "thousand talents plan" project and the help of Cornell University's high energy synchrotron radiation light source Corresponding author: researcher Liu Shengzhong, Associate Professor Zhao Kui, associate professor Aram amassian