Charge collection and absorption-limited sensitivity of x-ray photoconductors: Applications to a-Se and HgI2

A generalized expression for charge carrier transport and absorption-limited sensitivity of x-ray photoconductors is derived by analytically solving the continuity equation for both holes and electrons considering the drift of electrons and holes in the presence of deep traps. The normalized sensitivity equation is applied to stabilized a-Se and HgI2. In the latter case, the sensitivity model is fitted to published data to determine the electron and hole ranges (6.4×10−6 cm2/V and 7×10−8 cm2/V, respectively) in screen-printed polycrystalline HgI2.