Zn-doped Pb/Sn hybrid perovskite solar cells: Towards high photovoltaic performance

Achieving a low-toxicity mixed Sn/Pb halide perovskite solar cell with the higher performance and lower cost is still a major challenge. Furthermore, the element Zn was incorporated as a substitute cation for the toxic element Pb into the CH3NH3Sn0.25Pb0.75I3 perovskite compound, as a result of its significant properties such as non-toxic nature, inability to oxidize, and abundance on earth. Thus, the structures of Zn-doped Pb/Sn hybrid perovskite solar cells (PSCs) were introduced and studied. The results showed that 3% Zn-doping improved the crystal quality and surface coverage, increased the grain size (up to about 1 mu m), and reduced the non-radiative recombination mechanism by increasing the lifetime of carriers. In general, it significantly improved the photovoltaic performance of this type of solar cell. In particular, CH3NH3Pb0.72Sn0.25 Zn0.03I2.94Cl0.06 compound with a yield of 11.68% showed the highest photovoltaic performance with the lowest Pb compared to the sample without Zn-doping (Zn-0%) with a yield of 4.30%. The findings provide a new area for further research on lead reduced hybrid perovskite solar cells.