NOVELTY - The method involves providing a substrate (101). A sequence of layers of semiconductor material forming a solar cell is deposited on a separation layer (103c). The separation layer is etched when temperature of a thin flexible support and layers of semiconductor material decreases such that the support and attached layer curl away from the substrate having difference in coefficient of thermal expansion of the support and the adjacent semiconductor material, where the substrate is composed of gallium arsenide, and the separation layer is composed of gallium aluminum and arsenic.    USE - Method for selectively freeing an epitaxial layer from a single crystal substrate during solar cell fabrication process.    ADVANTAGE - The method enables utilization of surfactants to reduce threading dislocations in active regions, thus improving overall solar cell efficiency. The method allows introducing a chemical element into a reactor during growth of a metamorphic layer to improve surface characteristics of the layer.    DETAILED DESCRIPTION - The method allows forming a subcell composed of an gallium, indium and phosphide, gallium and arsenic, gallium indium and arsenic, gallium, arsenic and antimony, or gallium indium, arsenic and nitrogen emitter region and an indium, gallium and phosphide, gallium and arsenic, gallium, indium and arsenic, gallium, arsenic and antimony, or gallium, indium, arsenic and nitrogen base region, and another subcell composed of indium, gallium and phosphide emitter layer and a gallium and arsenic or gallium, indium and arsenic base layer. The transition material is composed of indium, gallium, aluminum and arsenic.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a solar cell after deposition of semiconductor layers on a growth substrate.    Substrate (101)    Separation layer (103c)    Back surface field layer (113)    Barrier layers (115, 117)    Metamorphic layer (116)    Window layer (118)    High band gap contact layer (122)