Effect of Metal ion doping on Perovskite Materials: Defect Mediated Charge Transfer, Energy Transfer and Carrier Mobility

Prof. Hirendra N. Ghosh
Director
National Institute of Science Education and Research (NISER)
Jatni, Khurda, Ordisha, India

Host: Tim Lian

Abstract
Metal-ion-doped halide perovskites exhibit unique optical and electronic properties, making thempromising for solar cells, light harvesting, and optoelectronic devices. However, the photophysical mechanisms governing charge-carrier dynamics in Mn/Eu-doped perovskites remain poorly understood. Here, we employ fluorescence up-conversion, femtosecond transient absorption, and terahertz spectroscopy to investigate excited-state dynamics and charge/energy transfer processes. We reveal defect-mediated and phonon-assisted pathways controlling carrier dynamics in Mn- and Eu-doped halide perovskites. In Mn-doped CsPbBr3, charge and energy transfer coexist, while Eu doping induces contrasting effects depending on the host lattice, including defect-mediated energy transfer, retarded hot-carrier cooling, and enhanced photoconductivity. Extending to lead-free Cu-doped Cs_AgBiBr6, Cu incorporation improves photoconductivity while slowing carrier mobility decay. These findings establish doping-driven strategies to manipulate carrier dynamics for next-generation optoelectronic devices.