Studies on fabrication and characterization of a ZnO/p-Si-based solar cell

Abstract

A kind of solar cell with the n-ZnO/p-Si hetero-junction interface structure has been fabricated by using DC magnetron sputtering, and its photovoltaic (PV) property is investigated by using the current–voltage ( I – V ) measurement under AM 1.5 illumination. The light I – V curves show a strong bias-dependent change and the photo-electric conversion efficiencies in the range of 0.7–1.14% have been achieved. The largest values of open circuit voltage ( V o c ) and short circuit current ( J s c ) were about 400 mV and 17.27 mA/cm 2, respectively. The crossover behavior of the dark and light I – V curves suggests that the recombination current arising from the interface states contributes to the bias dependence of the light I – V curve. The Si 2p spectra at the interface of ZnO/p-Si confirm the complexity of the interface quality and the existence of a large number of interface states. The bend behavior arising from the back contact barrier and the series resistance up to 50 Ω obtained from the dark I – V curve are also confirmed to be the crucial factors for achieving a good performance of the ZnO/p-Si-based solar cell.