Ultrathin high-efficiency solar cells based on AIIIBV/Ge heterostructures for space applications

The analysis of the prospects for the creation of ultrathin, lightweight and highly efficient solar cells based on AIIIBV/Ge heterostructures. Technological problems and prospects of various options are discussed. As the most promising method, it is proposed to use chemical thinning of AIIIBV/Ge heterostructures using a temporary technological carrier. A solar cell grown on a germanium substrate with a contact grid, an antireflection coating and radiation-proof glass, but without a back metal contact, is glued face-on to a technological carrier. Next, the Ge substrate is etched to the desired thickness and a back contact is created, and the carrier is removed by heating. This technique makes it possible to thin the Ge substrate to several tens of microns and significantly increase the percentage of yield of suitable devices almost without the risk of destroying the heterostructure. Measurement of the current-voltage characteristics of a thinned solar cell showed that for the terrestrial spectrum, the values of the parameters of the thinned sample coincide with the initial values. The idling voltage is 2.67 V, the current density is 14 mA/cm2.This opens up the possibility of creating highly efficient thin and light solar cells for space batteries based on currently mass-produced heterostructures - AIIIBV/Ge.