[en] The traditional way of doing gamma-ray spectrometry with semiconductor detectors depends on being able to collect the ionization charge. In most cases, hole trapping limits the spectrometric performance of room-temperature detectors made from compound semiconductors. Recently it has been shown for thick HgI₂ detectors that significant improvement can be produced by using a technique of unconventionally short differentiation of the detector pulses. The present paper presents the concept underlying the technique and gives its theoretical background. The method consists of measuring the amplitude of ionization current pulses before charge collection is completed rather than measuring the amount of charge collected. Hole collection is obviated, and the transport of electrons becomes the most-important consideration. The conditions under which this novel method can be applied to various semiconductor materials are discussed. Two different approaches toward the electronic implementation of the technique are compared