Optical wireless power transmission using CIGS solar cells

CIGS solar cells are promising light-receiving elements for optical wireless power transmission (OWPT) systems because they are inexpensive and receive light in the long wavelength range that is relatively safe for human eyes. A photoelectric conversion efficiency ηpv of the CIGS solar cell (10 mm x 10 mm) on a metal substrate was examined under a 1064 nm laser irradiation. We obtained ηpv values of 31.2% and 26.8% under a 1064 nm laser irradiation of 0.9 W/cm² (84 mW) and 2.6 W/cm² (244 mW), respectively. In anticipation of social implementation, we also demonstrated the influence of the size of the laser irradiation area on the conversion efficiency of CIGS solar cells. The photoelectric conversion efficiency did not change when the irradiated area was varied. These results could expand the possibility of applying CIGS solar cells to OWPT systems.