Effects of Zn2+ ion doping on hybrid perovskite crystallization and photovoltaic performance of solar cells

To achieve a reproducible perovskite film with full surface coverage, Zn2+ ions are introduced to partially replace Pb2+ ions in this work. Results indicate that the crystallization and formation of CH3NH3Pb1-xZnxI3 film with micrometer grain size could be changed by the micro-strain for lattice shrink. The bandgap and optical properties of perovskite films are improved due to trace amounts of Zn2+ ion dopant. More importantly, the solar cell device based on the Zn-doped perovskite film shows an increment in photocurrent of 21.13 mA cm(-2) and power conversion efficiency (PCE) of 16.6%. Electrochemical impedance spectroscopy (EIS) measurements reflect that the charge recombination resistance and charge accumulation capacitance of devices based on MAPb(0.98)Zn(0.02)I(3) film are lower than that of the control device. However, present results also implied that MAPb(1-x)Zn(x)I(3) films are still necessary to be extensively developed and optimized for further enhancing the device photovoltaic performance.