Crystalline silicon photovoltaic cells used for power transmission from solar-pumped lasers: I. Light trapping concepts

We have proposed a light trapping concept for crystalline silicon photovoltaic (PV) cells used for power transmission from solar-pumped lasers (SPLs) emitting at 1064 nm. The underlying mechanism is multiple reflection between a multilayered angle-selective filter on the front surface and a diffuse reflector on the rear surface of the cell. For the stationary use and optical fiber connection of the SPL-PV combination in which the incident angles of the laser light to the PV cells (phi) change within 5-10 degrees, double-cavity bandpass filters realize the required angle selection function. When the SPLs illuminate moving electric vehicles equipped with the PV cells at larger. values, shortpass filters are appropriate. These specially designed angle-selective filters provide significant light trapping performance and consequently absorbances higher than the Yablonovitch limit up to phi = 45 degrees. The fact that the present light trapping configuration requires no microfabrication processes is also a great advantage over two-and three-dimensional photonic crystal structures. (C) 2018 The Japan Society of Applied Physics.