Energy response of AlGaAs soft X-ray photon counting detectors

A variety of new types of detectors based on wide band gap materials have been developed for soft X-ray spectroscopy applications (e.g. GaAs, SiC, diamond). In this report we describe the spectroscopic performance of a simple p-i-n diode fabricated on AlGaAs. The energy response of the diode, operating in photon counting mode, at room temperature has been investigated using fluorescence from a number of high purity materials. X-ray spectra over the energy range 5 keV-25 keV show this type of diode can be used for spectroscopy with promising energy resolution ( ∼ 1.3 keV) at 30°C and excellent linearity.