Graphene is an attractive material for optoelectronics and photo detection applications because it offers a broad spectral bandwidth and fast response times. However, weak light absorption and the absence of a gain mechanism that can generate multiple charge carriers from one incident photon. Recently, a gain of 10^8 electrons per photon using hybrid Silicon-Graphene photo detector covered with a layer of quantum-dots was demonstrated (G.Konstantatos et al., Nature Nanotechnology, 10.1038/NNANO.2012.60). IFAE has recently started a collaboration with the ICFO on this issue, we will describe the scope of the project and the basic physics of the new technology.