Exploratory Corrugated Infrared Hot-Electron Transistor Arrays

In this study, we investigated a 5x8 corrugated infrared hot-electron transistor IHET array with a common base configuration. We found the IHET structure improved the photocurrent-to-dark current ratio by a maximum factor of six compared to the basic quantum well infrared photodetector QWIP structure. This improvement is consistent with the hot-electron distributions created by the thermal and photo-excitations within the detectors. The study also showed that there is no electrical cross-talk among individual detectors, even though they share the same emitter and base contacts. Thus, the IHET structure is compatible with existing electronic readout circuits for photoconductors in producing sensitive focal plane arrays. Though not essential in this study, the apparent barrier height of the filter in the present material was higher than the designed value. This higher barrier height can be attributed to the finite p-type doping density in the material.