A method and structure providing an optical sensor having an optimized Ge—Si interface includes providing a substrate having a pixel region and a logic region. In some embodiments, the method further includes forming a trench within the pixel region. In various examples, and after forming the trench, the method further includes forming a doped semiconductor layer along sidewalls and along a bottom surface of the trench. In some embodiments, the method further includes forming a germanium layer within the trench and over the doped semiconductor layer. In some examples, and after forming the germanium layer, the method further includes forming an optical sensor within the germanium layer.