Overview of Concentrator Solar Cells and Analysis for Their Non-Radiative Recombination
Abstract
Concentration photovoltaics (CPV) has great potential of higher efficiency and lower cost compared to conventional crystalline Si PV and thin-film PV. Although excellent results for CPV cells such as 27.6%, 29.3%, 44.4% and 47.1% with Si, GaAs, InGaP/GaAs/InGaAs 3-junction and AlGaInP/AlGaAs/GaAs/GaInAs/ GaInAs/GaInAs 6-junction concentrator cells have been demonstrated, there are still problems to be solved. This paper overviews concentrator solar cells. In addition, this paper presents analytical results for efficiency potential of CPV cells based on analysis of non-radiative recombination loss in CPV cells. Concentrator Si, GaAs, CIGS and InGaAs/InGaAs 3-junction solar cells have efficiency potential of more than 34%, 36% 31% and 50%, respectively, by realizing ERE (external radiative efficiency) of 20% and reducing series resistance. This paper also presents our recent approaches for PV-powered vehicle applications and static low concentrator InGaP/GaAs/InGaAs 3-junction solar cell module with efficiency of 32.84%, and so forth.