INTERMEDIATE TEMPERATURE MOLECULAR BEAM-EPITAXY GROWTH FOR DESIGN OF LARGE-AREA METAL-SEMICONDUCTOR-METAL PHOTODETECTORS

Large-area metal-semiconductor-metal (MSM) photodetectors are fabricat ed on molecular beam epitaxy (MBE) grown GaAs material at growth tempe ratures ranging from 250 to 500-degrees-C. it is shown that materials grown at intermediate temperatures are a suitable choice for large-are a, high photocurrent detectors. Particularly, MSM devices made from ma terial grown at around 350-degrees-C have a dark current of the same m agnitude as those grown at lower temperatures while having a substanti ally larger photocurrent. Higher low-field mobility at intermediate te mperatures should give these devices speed advantage as well. A change of close to 4 orders of magnitude in dark current and more than 2 ord ers of magnitude in light response is observed for this temperature ra nge.