Analysis for efficiency potential of high‐efficiency and next‐generation solar cells

Abstract

Abstract This paper overviews photovoltaic R&D projects in Japan. Recently, world‐record and second highest efficiencies of various types of solar cells have been demonstrated under the New Energy and Industrial Technology Development Organization Project: 44.4% (under concentration) and 37.9% (under 1 sun) InGaP/GaAs/InGaAs inverted metamorphic 3‐junction solar cells by Sharp, 26.7% single crystalline Si heterojunction back‐contact solar cell by Kaneka, 22.3% copper indium gallium selenide solar cell by Solar Frontier, a‐Si/μc‐Si/μc‐Si thin‐film triple‐junction solar cell with stabilized efficiency of 14.0% by AIST, 11.9% dye‐sensitized solar cell by Sharp, and 11.2% organic solar cell by Toshiba. This paper also presents efficiency potential of high‐efficiency and next‐generation solar cells analyzed by considering external radiative efficiency, open‐circuit voltage loss, and fill factor loss. Efficiency potential of crystalline Si, GaAs, III‐V compound 3‐junction and 5‐junction, CIGSe, CdTe, CZTS(Se), multiquantum well, and quantum dot and perovskite solar cells is shown to be 28.5%, 29.7%, 40%, 43%, 26.5%, 26.5%, 20%, 25.8%, and 24.9% under 1 sun, respectively.