HOLE DOMINATED TRANSPORT IN INGAAS METAL-SEMICONDUCTOR-METAL PHOTODETECTORS

We report the direct measurement of the intrinsic photocurrent respons e of both top and back illuminated planar metal-semiconductor-metal st ructures. We directly observe the temporal dynamics of the hole transp ort dependence on applied bias and the initial spatial distribution us ing a near infrared tunable femtosecond light source and electrically biased: structures. The increased hole transit time of back illuminate d structures can be completely understood in terms of the hole velocit y and the initial spatial distribution of the carriers. Additionally, we report the fastest directly measured 50 mu m diameter InGaAs photod etector with a 26 ps full width at half maximum. (C) 1995 American Ins titute of Physics.