Two-coordinate position sensitive amorphous silicon photodetectors

Position-sensitive photodetectors (PSD) on the basis of a p-cSi/a-Si:H structure have been developed. Thin undoped hydrogenated amorphous silicon films were deposited by the homogeneous chemical vapour deposition (Homogeneous CVD) method on a p-type crystalline silicon (c-Si) substrate of 10 Omega cm resistivity. Strip parallel lateral aluminium position electrodes were evaporated on the a-Si:H film in one and two-coordinate geometry. The active detector area was 0.36 cm(2). The position characteristics, sensitivity dependence on light intensity and photovoltage spectral dependence of the prepared PSD were measured. The position characteristics are symmetric to the zero and linear in the 70% of the active area. To investigate the homogeneity and the electrode influence two-coordinate position characteristics (topograms) were recorded. (C) 1999 Elsevier Science S.A. All rights reserved.