EVALUATION OF SOLID-STATE DETECTORS FOR ULTRAVIOLET RADIOMETRIC APPLICATIONS

The realization and dissemination of ultraviolet spectral responsivity scales at the 0,1% level require a solid-state detector with a predic table, and preferably an invariant, spectral responsivity. Unfortunate ly, the most widely used detectors for the ultraviolet, silicon photod iodes, have a spectral responsivity that varies rapidly in the ultravi olet due to multiple ionization and recombination effects. This paper describes the properties of alternative wide-bandgap photodiodes such as GaAsP and GaP, together with specially developed detectors based on SiC. These devices are ''solar blind'' to various degrees, thus offer ing significant advantages over silicon photodiodes in certain applica tions. Measured quantum efficiency for all these types of photodiode i s presented, together with an evaluation of permanent and short-term c hanges in quantum efficiency of the detectors following exposure to UV radiation.