Development of the ultra-thin GaAs photovoltaic devices for high-efficiency and semi-transparent application

Abstract The semi-transparent type of photovoltaic (PV) cell consisting of the ultra-thin GaAs was demonstrated. Applying the grid shaped metal contact for both the top- and rear-side interface and extremely reducing an absorption thickness of the GaAs absorber layer to 100 nm in thickness, the PV device transferred to the quartz substrate via the epoxy resin indicated a significant optical transparency in the optical wavelength range. Compared with the PV samples with the rear planer-type of metal contact working as well as a backside reflector, reduction of the short circuit current density ( J sc ) is 1.71 mA cm −2 estimated in the semi-transparent samples. An anti-reflection coating composed by dual dielectric layer of ZnS and SiO 2 was also applied to the semi-transparent GaAs PV device, resulted in improved in J sc to 12.3 mA cm −2 and increased transmittance was observed due to the suppression of surface reflectance. Finally, the conversion efficiency of the semi-transparent type of GaAs PV reached 9.86% and 27.4% of average visible light transmittance was obtained.