TECHNOLOGY FOCUS - ELECTRONICS - Preferred Process: The process further comprises: processing detached monocrystalline silicon layer as a solar cell; refurbishing the substrate for re-use; determining at least one of number of the openings, a size of the openings or a spatial orientation of the openings based on at least one of thickness of the intermediate layer and a composition of the intermediate layer or an etch chemistry; and processing the detached other monocrystalline silicon layer as another solar cell. The step of forming the intermediate layer comprises: epitaxially growing the intermediate layer on the substrate; epitaxially growing one of silicon-germanium or silicon- arsenic on the substrate; and implanting an impurity into the substrate. The step of forming the monocrystalline silicon layer comprises: forming holes in the intermediate layer; and epitaxially growing silicon from the substrate through the holes and over the intermediate layer. The process further comprises: forming another intermediate layer on the monocrystalline silicon substrate; forming another monocrystalline silicon layer on the other intermediate layer; forming other electrical features in the other monocrystalline silicon layer; forming other openings in the other monocrystalline silicon layer; and detaching the other monocrystalline silicon layer from the substrate by selectively etching the other intermediate layer through the openings after the detaching the monocrystalline silicon layer from the substrate. In the process of forming many solar cells further comprises: refurbishing the substrate after the selectively etching the first intermediate layer and prior to the forming the second intermediate layer; and forming openings in the first single crystal silicon layer, where the selectively etching the first intermediate layer comprises etching the first intermediate layer through the openings. The step of forming the first single crystal silicon layer comprises: epitaxially growing the first single crystal silicon layer on the first intermediate layer; and the forming the first intermediate layer comprises one of epitaxially growing the first intermediate layer on the substrate, implanting an impurity into the substrate or forming oxide or nitride on the substrate. Preferred Components: The refurbishing comprises at least one of etching residue from a surface of the substrate, polishing the substrate or re-growing a portion of the substrate. In the semiconductor structure at least one of number of the openings, size of the openings or spatial orientation of the openings is based on at least one of thickness of a sacrificial intermediate layer, composition of the sacrificial intermediate layer or an etch chemistry for detaching the single crystal silicon solar cell from the sacrificial intermediate layer.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The impurity comprises one of germanium or arsenic. The intermediate layer is composed of one of oxide or nitride. EXAMPLE - No suitable example given.