Characterisation and modelling of a two terminal visible/infrared photodetector based on amorphous/crystalline silicon heterostructure

In this work, we report on the detailed characterisation of a two terminal visible/infrared tuneable photodetector both in steady state and transient operation. The device consists of a n-doped amorphous silicon/intrinsic amorphous silicon/p-doped amorphous silicon carbide multilayer structure grown by PECVD on a p-type crystalline silicon wafer doped by a phosphorus diffusion. The steady state behaviour is analysed by an analytical model, which takes into account the absorption coefficients, the diffusion length, the mobility-lifetime product and the layer thicknesses and allows us to obtain quantitative information on the materials inside the device. The linearity of the detector response is also presented. On the basis of the transient response measured by means of a test circuit simulating the row select TFT and the data line capacitance by discrete components, driving of 2-D array of VIPs is discussed. (C) 2001 Elsevier Science B.V. All rights reserved.