The roles of electric fields and illumination levels in passivating the surface of silicon solar cells

The back surface recombination velocity (BSRV) of operating silicon solar cells has been modulated by an externally applied gate voltage and illumination through a semi-transparent MOS structure. All three voltage bias modes (accumulation, depletion and inversion) of this MOS system are examined. In addition, the effects of gate bias voltage, illumination (or carrier injection level) and oxide charge on the BSRV and solar cell performance are investigated. The effects of electric field and illumination are found to play key roles in achieving a low BSRV. Methods of achieving a low BSRV with this structure are described.