Charge transport in arrays of semiconductor gamma-ray detectors.

We analyze the effects of electrode size on performance of arrays of semiconductor gamma-ray detectors, especially when there is significant charge trapping. With large electrodes, motions of holes and electrons are of equal importance, but when the positive electrode is segmented into an array of small elements the contributions of holes to the output, and hence the effects of hole trapping, are much less significant. The implications of this analysis for the design of practical detector arrays are discussed, and some preliminary experimental verification of the theory is presented.