NOVEL TUNABLE FAR-INFRARED DETECTOR BASED ON A QUANTUM BALLISTIC CHANNEL

A new tunable far infrared detector based on a quantum ballistic chann el in the asymmetric split-gate structure is proposed and considered t heoretically. The asymmetric split-gate provides a long constant width channel with a rather sharp asymmetric narrowing at its end. It is su pposed that only the lowest 1st subband in a wide channel is occupied by electrons. There is a thick barrier for these electrons in the narr ow channel, so the dark current reduces almost to zero. Due to the asy mmetric variation of the channel width the electrons can pass the narr ow region of the channel under illumination with the photon energy clo se to subband separation. The Ampere-Watt responsivity of the photovol taic detector is evaluated. The advantage of the proposed detector is a possibility of tuning by a gate voltage and the small response time.