Andrew LaBella publishes his first paper on “Picosecond Time Resolution with Avalanche Amorphous Selenium.”This paper appeared as a supplementary cover in ACS Photonics, vol. 6, issue 6. Congratulations Andy!
Picosecond timing in an avalanche amorphous selenium semiconductor is achieved by implementing Nano-Frisch grids along the collecting electrode to form a multiwell structure. The induced photocurrent following optical impulse exposure is independent of carrier motion outside the wells resulting in unipolar time-differential charge sensing via extended-state hot hole transport. This is the first experimental report of avalanche gain and picosecond time-resolution using an amorphous semiconductor. Further analysis suggests we may be able to achieve sub-100 picosecond coincidence timing resolution in time-of-flight PET using our multiwell selenium semiconductor as the photodetector.