In this paper we show for the first time the possibility to direct grow and tune the size and optical properties of high quality InAs/GaAs quantum dots on transferable crystalline silicon nanomembranes. The transferable silicon nanomembranes have been grown via in-situ H 2 prebake of porous silicon in Ultra High Vacuum Chemical vapour Deposition (UHV-CVD) reactor. Flat and continuous transferable crystalline nanomembranes with thicknesses below 30 nm have been obtained. The mechanical strain in the silicon nanomembranes has been tuned via sintering temperature between 900 and 1100 C for the direct crystalline growth of transferable InAs/GaAs (QDs)/Si foils. The size and band gap energy of these InAs/GaAs quantum dots are tuned via strain engineering in silicon nanomembranes. Several advanced techniques such as Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron …