ULTRA-FAST DETECTORS USING DOPED NANOCRYSTAL INSULATORS

An efficient and ultrafast sensor for X-ray and UV radiation based on doped nanocrystals. These doped nanocrystals consist preferably of impurity-activator doped wide band gap II-VI semiconductors. They yield high efficiency and short recombination time radiation-sensitive phosphors which in response to radiation emit visible light easily detected by conventional sensors such as Si sensors. The combination of pulsed UV/X-ray sources with efficient and ultrafast sensors will yield sensors with increased signal to noise ratio. In a preferred embodiment, thin films of doped nanocrystals are used for generating visible radiation, which can be imaged with a conventional Si-based camera. Other applications also include the use of doped nanocrystals of piezoelectric materials to sense pressure, of pyroelectric materials to sense heat, and of ferroelectric materials to sense electric fields.