Photocarrier response time scanner

We have used the dependence of the response time after short laser pulses on background light intensity in hydrogenated microcrystalline silicon to study the properties of a two-dimensional image sensor application. A coplanar readout scheme has the advantage of a simple sample structure, however, the signal-to-noise ratio is acceptable only in the perpendicular readout of a p–i–n detector. The response time map reflects the change of both the resistivity and capacitance under varying local illumination. A camera speed of 10 frames per second with a 50 by 50 pixel resolution is reached on a 2 cm 2 detector. 2002 Published by Elsevier Science B.V.