Avalanche photoionization detector

This paper reports a microfluidic gas sensor termed avalanche photoionization detector (APID). The APID employs miniaturized vacuum-UV (VUV) lamp as a photoionization source to ionize volatile organic compounds (VOCs) within a microfluidic ionization chamber made of a MgF2 substrate bonded to an etch-through silicon microfluidic channel. The resultant electrons are collected by a reversely-biased avalanche P/N junction and subsequently undergo an avalanche process within the junction's depletion region, resulting in a substantial internal gain.