The Role of Synthesis Parameters on Crystallization and Grain Size in Hybrid Halide Perovskite Solar Cells

Antisolvent method has been widely applied to fabricate hybrid halide perovskite solar cells. However, the quality of perovskite film is unable to effectively control for the excessively fast crystallization. In this work, we investigated the effect of precursor concentration and spinning speed as well as additive CH3NH3Cl on quality perovskite film and thus the performance solar cells. The growth of crystal toward the, orientation parallel to the direction of facet (002)/(004) slows down as the concentration and Spinning speed increases. The lattice constants points out the expansion of crystal' site in the direction along the c-axis of around 0.04 (A) over circle due to the size difference between I and Cl ions. A vertical growth,mechanism;was propoSed to elaborate the crystallite growth of CH3NH3PWI3(CI) Perovskite,film. Consequently, the perovskite solar cell, efficiency impressively 'increases from similar to 12% to similar to 1.6% along enlarging crystal size. Various advanced characterization `techniques including ultrafast speCtroscop,y and electroniCimpeclanCe spectroscopy elucidated that an optimal film with large grain size, and less defect states, could result in the enhancement of -charge transport and collection efficiency.