Efficient deep UV detection in polycrystalline diamond by double collection mechanism

The possibility of combining both photocurrent and photoelectron signals in a single diamond UV detector with optimized spectral collection efficiency is investigated. Photoconductive and photocathode devices exhibit different spectral photoresponses which can be combined in a three-electrode device able to collect both photocurrent and photoelectron signals. Hydrogenated and CsI-coated diamond films have been used for the realization of the three-electrode detector. An improvement of the UV device responsivity is obtained in vertical photocurrent and photoelectron (VPCPE) collecting structure, overcoming the problem of the efficiency losses occurring at short wavelengths in photoconductive devices. Double collection in two terminal vacuum structures by using the diamond surface as a capacitively coupled third electrode is also investigated.