Multiferroic Bi2FeCrO6 based p-i-n Heterojunction Photovoltaic devices
Photovoltaic devices made of ferroelectric films are being widely studied, due to the efficient charge separation driven by the internal polarization as well as above-bandgap generated photovoltages. These features may enable power conversion efficiencies (PCE) exceeding the Shockley–Queisser limit, which characterizes conventional semiconductor-based solar cells. However, improving the PCE of such devices is still a challenge, mainly due to the weak charge transport and collection induced by recombination of photocarriers. Here, we formed p−i−n heterojunction devices based on double-perovskite multiferroic Bi2FeCrO6 thin films. The latter acts as an intrinsic absorber, sandwiched between hole- and electron-transporting layers, a p−type NiO and an n−type Nb-doped SrTiO3 semiconductor, respectively. Under 1 sun illumination, the optimized p−i−n device yields an open-circuit voltage of 0.53 V and a short-circuit current density of 8.0 mA cm-2, leading to a PCE of ca. 2.0%, a four-fold enhancement compared to that of the i−n device architecture.