Effect of Mn doping on the photovoltaic properties of multiferroic composite nanowire arrays

Abstract

The lead-free inorganic perovskite metal oxide, BiFeO₃ (BFO), presents promising potential for photovoltaic applications within solar cells. However, its limited light absorption and carrier mobility constrain the enhancement of its photovoltaic conversion efficiency (PCE). Therefore, in this study, Mn was doped into BiFeO₃ to form Bi(Fe,Mn)O₃ (BFMO), which reduced the band gap of BFO. Additionally, a TiO₂ nanowire array transport layer was introduced to facilitate carrier transport. At a Mn doping concentration of 20%, TiO₂/BFMO core–shell nanowire arrays exhibited superior light absorption compared to TiO₂/BFO, with a reduction in bandgap from 2.05 eV to 1.90 eV. Surprisingly, the PCE increased from 0.1177% for the TiO₂/BFO core–shell nanowires to 0.7979% (almost a 6-fold improvement). Based on these findings, Mn doping in multiferroic composite nanowire arrays demonstrates considerable potential for improving photovoltaic properties in the production of diverse solar cell types.