Modification of photovoltaic laser-power ($\lambda$ = 808 nm) converters grown by LPE

Laser-power converters for the wavelength $\lambda$ = 808 nm are fabricated by liquid-phase epitaxy (LPE) on the basis of $n$-Al$_{0.07}$Ga$_{0.93}$As-$p$-Al$_{0.07}$ Ga$_{0.93}$As-$p$-Al$_{0.25}$Ga$_{0.75}$As single-junction heterostructures. The converters are tested with uniform (pulse simulator) and partly nonuniform (laser beam) illumination distribution over the photoreceiving surface. In the former case, a monochromatic efficiency of $\eta$ = 53.1% is achieved for samples with an area of $S$ = 4 cm$^2$ at a power of 1.2 W. At $S$ = 10.2 mm$^2$ the efficiency is 58.3% at a laser power of 0.7 W.