Carbon edge response of diamond devices

Near edge responsivity in diamond x-ray detectors has been used to confirm the carrier loss mechanism as recombination due to diffusion into the incident electrode. We present a detailed study of the bias dependence of the diamond responsivity across the carbon k-edge. The carrier loss is modelled by incorporating a characteristic recombination length into the absorption model and is shown to agree well with Monte Carlo simulated carrier losses. Using the high sensitivity to the x-ray absorption depth, the responsivity is converted to a near edge x-ray absorption fine structure pattern allowing easy identification of absorption mechanisms.