In one inventive aspect, a thin film device is manufactured by (a) forming a porous semiconductor layer in the form of a thin film on an original substrate, the formation being immediately followed by (b) separation of the thin film by a lift-off process from the original substrate; (c) transfer of the thin film to a dummy support, the thin film not being attached to the dummy support; (d) fabrication of a device on top of the thin film; and (e) transfer and attachment of said device on said thin film on a foreign substrate.