Fe²⁺/Fe³⁺ Doped into MAPbCl₃ Single Crystal: Impact on Crystal Growth and Optical and Photoelectronic Properties

As one type of organic–inorganic hybrid lead halide perovskites, MAPbX 3 has attracted immense interests in applications of optoelectronic devices because of its remarkable properties. However, the toxicity of lead is considered as the biggest concern which cause environment pollution. The introduction of impurity ions deliberately to replace Pb in the crystal structure is deemed to be an effective way to minimize the effect of lead toxicity while maximizing energy conversion efficiency. On the other hand, iron (Fe) impurities are inevitable impurities present in raw materials. However, the influence of Fe ions on both crystal structure and photoelectric properties is still unknown. So, it is worth exploring the effects of heterovalent Fe 2+ /Fe 3+ on hybrid lead halide perovskite. Here, we first incorporate Fe 2+ /Fe 3+ into the crystal lattice of MAPbCl 3 single crystals, and we have successfully grown MAPbCl 3 single crystals with various doping concentrations of Fe 2+ /Fe 3+ (0, 10, 20%) and report the crystal growth process, crystal structures, and optical properties of MAPbCl 3 single crystals doped with Fe 2+ /Fe 3+ . Moreover, the effect of Fe 2+ /Fe 3+ incorporated into MAPbCl 3 single crystals on the optoelectronic properties was investigated by utilizing planar photodetectors.