Upconversion of Bi4Ti3O12:Er and its evaluation in silicon solar cell yield

Abstract

Using the sol–gel method, Er3+-doped Bi4Ti3O12 films were prepared on monocrystalline silicon substrates. The current–voltage characteristics for the prepared structures were measured using a 300 W solar simulator at air mass 1.5 (AM1.5) and at a frequency of 50–60 Hz. In general, all samples maintained a clearly visible diode-like behavior. It was observed that the reference cell had a lower energy conversion efficiency compared to the silicon solar cell modified with the BIT:Er films adhered to its back contact in all cases under AM1.5 illumination. The 2 mol% sample reached an open circuit voltage of 544 mV and a short circuit current of 39.8 mA/cm2 with a 2.2% excess over the reference solar cell efficiency.