Materials suitable for fabricating optical monitors include amorphous, polycrystalline and microcrystalline materials. Semitransparent photodetector materials may be based on silicon or silicon and germanium alloys. Conductors for connecting to and contacting the photodetector may be made from various...http://www.google.com/patents/US6670599?utm_source=gb-gplus-sharePatent US6670599 - Semitransparent optical detector on a flexible substrate and method of making
