High efficiency textured silicon solar cells based on an ITO/TiO2/Si MOS structure and biasing effects

Abstract

In this study, the high conversion efficiency of textured silicon solar cells based on an ITO/TiO2/Si metal–oxide–semiconductor (MOS) structure and biasing effects was experimentally demonstrated. An impressive conversion efficiency of >20% was obtained through an increase in the absorption volume and through the efficient collection of the generated photo-carriers when the biasing voltage was applied on the ITO-transparent electrode. The optical reflectance, dark current–voltage (I–V), external quantum efficiency (EQE) and photovoltaic current density–voltage (J–V) under one-sun AM 1.5G illumination of the MOS structure solar cells without voltage biasing were characterized firstly. Then the photovoltaic J–V curves of the MOS structure solar cells with biasing voltages from 0 to 3V were measured and compared. Significant increases in short-circuit current and conversion efficiency were observed when the biasing voltage was increased from 0 to 3V using an external voltage power supply. In addition, the integration of a photovoltaic biasing source using a series of connected p–n junction solar cells (instead of an external voltage power supply) with a MOS structure solar cell on a ceramic platform to enhance the MOS structure solar cell efficiency was demonstrated for the first time in textured silicon solar cells.