Youth Chemistry Conference 2nd Youth Chemistry Conference booklet | Page 7

GUEST LECTURES Dr. Annie Ng Assistant Professor Department of Electrical and Computer Engineering, Nazarbayev University A novel cryo-controlled nucleation method for high efficiency perovskite solar cells Abstract A novel cryo-controlled nucleation technique is applied to synthesize organometal halide perovskite for solar cells (PSCs). A rapid reduction in the temperature causes a supersaturation condition in the precursor layer, prepared by solution technique, leading to a uniform nucleation sites for the subsequent crystallization phase. The low temperature condition inhibits the pre-mature crystallization of perovskites in the early stage before a uniform seed layer is formed and, thereby, decoupling the nucleation and crystallization phases. This approach allows the formation of a highly uniform nucleation layer and is crucial for the growth of perovskite films with excellent film quality. A power conversion efficiency (PCE) of 21.4 % for the champion PSC was achieved by using this perovskite growth method. The process of cryo-controlled nucleation method and the performance of the champion perovskite solar cell. Reference 1. Ng, Z. Ren, H. Hu, P. W. K. Fong, Q. Shen, S. H. Cheung, P. Qin, J.-W. Lee, A. B. Djurišić, S. K. Su, G. Li, Y. Yang, C. Surya. A cryogenic process for antisolvent-free high-performance perovskite solar cells, Adv. Mater. (2018) DOI:10.1002/adma.201804402.