PUB - Publikationen an der Universität Bielefeld

a-Si:H-based three-terminal three-color detectors are experimentally investigated. Transient properties of photocurrent after bias switching are studied in PINIP structures for the detection of either blue and green light (PI(1)NI(2)P) or green and red light (PI(2)NI(3)P) under different illumination intensities and under different voltages before and after bias switching. A reciprocal relationship between the delay times and the illumination intensity is established for both structures over a wide range of illumination intensity. Only for the larger intensities is a deviation from the reciprocal relation observed. The delay time, t(d Np), due to switching from negative to positive bias, determines the speed of the device. It is for both structures only moderately wavelength dependent, but it strongly depends on the switching voltage levels, V(N(egitive)) and V(p(ositive)). Optimized selection of V(1N) and V(1p) reduces the delay time of the PI(1)NI(2)P structure, speeding it up to the generally faster PI(2)NI(3)P structure. (C) 2000 Elsevier Science B.V. All rights reserved.