Dopant compensation in p-type doped MAPb1-xCuxI3 alloyed perovskite crystals

Tuning the optical and electrical properties of semiconductors by designed doping is the basis of most energy-related semiconductor optoelectronic devices. In this Letter, we report the dopant compensation effect of P-type doped MAPb(1-)(x) CuxI3 alloyed perovskite crystals. MAPb(1-)(x)Cu(x)I(3) single crystals were prepared by the inverse temperature crystallization method using cupric chloride (CuCl2) as the doping source. By XRD, XPS, STEM, and photoluminescence (PL) spectra analyses, we demonstrate that the doped cupric (Cu2+) ions can partially substitute lead (Pb2+) ions and form Cu-Pb based crystal semiconductor alloys of MAPb(1-)(x)Cu(x)I(3) with tunable bandgap by controlling the Pb/Cu ratio. More detailed XPS analysis of the doped crystal shows that the Cu2+ ions in MAPb(1-)(x)Cu(x)I(3) are partially reduced by I- ions, and the coexistence of two valence states of Cu species (Cu2+ and Cu+) was observed in the doped crystals. Hall results of MAPb(1-)(x)Cu(x)I(3) semiconductors show that the presence of reduced Cu+ ions impels the change of conductive type from weak N-type to P-type obviously, while the resistivity of doped MAPb(1-)(x)Cu(x)I(3) increases significantly from 10(4) to 10(7) omega cm. The defect-related optical fingerprints of cupric doped crystals were investigated in detail by temperature-dependent PL spectroscopy. The pristine MAPbI(3) perovskite crystal exhibits intrinsic donor bound exciton ((DX)-X-0) luminescence at low temperature (10 K), while the doped MAPb(1-)(x)Cu(x)I(3) perovskites exhibit donor-acceptor or bound exciton (A(0)X) peaks related to a Cu+ dopant in sequence with the increase in the Cu ion content. These results indicate that the doping of Cu2+/+ ions into the MAPb(1-)(x)Cu(x)I(3) crystal not only changes the semiconductor bandgap but also causes the dopant compensation. Published under an exclusive license by AIP Publishing.

Automated summary

This Letter reports the dopant compensation effect of P-type doped MAPb(1-)(x)CuxI3 alloyed perovskite crystals. The doped Cu+ ions change the conductive type of the crystal and significantly increase the resistivity. The doped crystals exhibit specific peaks related to Cu+ dopant in temperature-dependent PL spectroscopy.