Why use compound semiconductors?
Apart from its on-going development of micro channel plate optics, the Advanced Technologies Section is studying the suitability of several compound semiconducting materials, including GaAs, CdZnTe, TlBr, InP and HgI2. These all have band-gaps sufficiently high so they do not require cryogenic cooling but low enough that sub-keV spectral resolution may be achieved at hard X-ray energies. In addition, the materials are drawn from group III and V compounds and so have high enough atomic numbers to ensure high detection efficiencies above 10 keV.
