Large area direct X-ray conversion detector for protein crystallography

This work proposes a large area detector for protein crystallography based on an amorphous silicon (a-Si:H) thin film transistor (TFT) pixel array backplane and an overlying amorphous selenium (a-Se) photoconductor for direct conversion of incident X-ray into image charge. To achieve high sensitivity, avalanche multiplication in a-Se is adopted to make the detector sensitive to each incident X-ray. The use of a-Si:H technology promises large area imaging of protein diffraction patterns at less expense compared to existing CCD and image plate detectors. In addition, a theoretical analysis shows that the detector exhibits fast readout speed (readout time < 1 s), high dynamic range (~10⁶), and high sensitivity (~1 X-ray photon), thus validating the detectorpsilas use in protein crystallography.