High performance avalanche quantum dot photodetector for mid-infrared detection

Application of a multiplication region in the structure of a quantum dot infrared photodetector (QDIP) is studied. Device is based on separated absorption and multiplication layers at which the generated photocurrent is gained by avalanche multiplication and higher responsivity is expected. Numerical simulation of the device performance shows larger responsivity and specific detectivity () compared with a conventional QDIP. The operating temperature of proposed device is also increased to 150 K with higher responsivity about 6 A/W and specific detectivity of about at . The results also show acceptable signal-to-noise ratio of 11 dB at T 120 K. Dynamic behaviour of detector is also studied and frequency response calculations predict 3-dB bandwidth of device about 70 GHz.