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

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 3 V were measured and compared. Significant increases in short-circuit current and conversion efficiency were observed when the biasing voltage was increased from 0 to 3 V 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.