Silicon Solar Arrays for Laser Power Transfer Applications

Modern silicon photovoltaic (PV) cells have high external quantum efficiencies (>70%) from 900nm-1070nm, and are ideally suited as laser power receivers to match the wavelength of high power lasers available today. Silicon PV cells are $\sim 300\mathrm{X}$ less expensive than III-V photovoltaic cells making them economical alternatives for large area receivers. A large receiver benefits the laser side of a wireless power system by reducing the requirement for maintaining a small beam at a great distance and eases the wireless receiver design by allowing waste heat to be spread over a larger surface area. Finally, a silicon PV array can efficiently combine solar energy harvesting during the day, and laser energy power transfer at night with a single low-cost array. In this paper we study commercially available silicon solar cells, evaluate their suitability for a laser power converter, and discuss some of the system related aspects of fielding a laser power converter.