Optical radiation detection is conventionally performed using semiconductor detectors such as photodiodes and solar cells in which impinging illumination generates electron-hole pairs that are then sensed as electric current and/or electric voltage. Other types of optical radiation detectors include photoresistors and photoconductors that change electrical characteristics under illumination, based on materials such as polyvinylcarbazole and lead sulfide. In addition, one can use charge-coupled devices (CCD) to record images, for example in the field of digital photography.
There is a need for optical or electromagnetic radiation detection systems that have improved bandwidth, improved linearity and improved sensitivity.