Al$_{x}$In$_{y}$Ga$_{1-x-y}$P$_{z}$As$_{1-z}$/GaAs heterostructures for photovoltaic converters

The Al$_{x}$In$_{y}$Ga$_{1-x-y}$P$_{z}$As$_{1-z}$/GaAs graded-gap heterostructures were grown by the temperature gradient zone recrystallization with a liquid zone reciprocating, where energy band gap varied from 1.43 to 2.2 eV. The influence of technological parameters on the varying in the energy band gap of the grown Al$_{x}$In$_{y}$Ga$_{1-x-y}$P$_{z}$As$_{1-z}$/GaAs solid solutions is investigated. In the $p$-Al$_{x}$In$_{y}$Ga$_{1-x-y}$P$_{z}$As$_{1-z}$/GaAs heterostructure, the maximum energy band gap gradient of 10490 eV/cm is reached, and an increase in the external quantum efficiency is shown in the wavelength range of 500–900 nm.