Long wavelength response of unstressed and stressed Ge:Ga detectors

Abstract

Photoconductivity spectra of unstressed and stressed Ge:Ga detectors were measured. The ecperiments were performed with a polarizing step scan Fourier transform spectrometer using the synchrotron facility BESSY, which was operated in a dedicated mode with a low momentum compaction factor. By this way powerful and coherent synchrotron radiation below 5o cm-1 was generated. We observed a significant response of unstressed and stressed Ge:Ga detectors below 5o cm-1 and 25 cm-1, respectively. This response can be attributed to transitions between bound excited states or from bound excited states to the valence band. The results indicate that in germanium detectors a fraction of the recombining holes is captured into bound excited states