Dependence of the conversion efficiency of CIGS solar cells on the incident laser wavelength for optical wireless power transmission

CIGS solar cells for optical wireless power transmission were irradiated with four lasers having a wavelength of 635 nm, 850 nm, 1064 nm, and 1208 nm. We investigated the dependence of conversion efficiency on the incident laser intensity and device temperature. The highest conversion efficiency was 30.3% when irradiated with a 1064 nm light with 0.18 W cm −2 , followed by 850 nm, 635 nm, and 1208 nm, in that order. The conversion efficiencies decreased with a temperature change from 20 °C to 60 °C, with the rate of decrease being the smallest at 1064 nm and the largest at 635 nm.