Diamond-based vacuum UV photodetectors for space applications

During the last decade, many studies have addressed the use of synthetic diamond as sensing material for deep UV photon detection. Solar missions, as the Solar Orbiter and the Solar Probe will require UV photon detectors with unprecedented sensitivity at wavelengths lambda < 200 nm and radiation hardness. Diamond appears to be the ideal photosensitive material for such applications, as it is very solar blind (10(5) rejection ratio @ lambda > 230 nm and 107 above 400 nm), its very low dark current level avoids the use of cooling systems, has a high UV responsivity and it is radiation hard and chemically inert. This paper is a review of our recent results on the electro-optical properties of diamond and a comparative analysis and characterization of the performances of different diamond-based photodetectors in the vacuum UV. In addition, we will describe some of the photodetectors that are under development for space applications and that will exploit the properties of diamond.