Utilizing the high efficiency of the localized carrier extraction in the low-dimensional semiconductors within a PN junction, an InP-based InAs/InGaAs/InAlAs interband quantum well infrared photodetector has been investigated. Although the thermal energy is much less than the band offset, the detector still realizes photo response up to 1.93 μm. In addition, the detector shows the room-temperature external quantum efficiency of 7% and detectivity of 1.81 × 1010 cm /W without anti-reflection layer. Based on the above quantum efficiency value, an absorption coefficient of 1.1 × 104 cm−1 was also determined. It is clear that our work provides compelling evidences for the possibility of novel and low-cost infrared photodetector.

Here in this paper, we report a room-temperature operating infrared photodetector based on the interband transition of an InAsSb/GaSb quantum well. The interband transition energy of 5-nm thick InAs 0.91 Sb 0.09 embedded in the GaSb barrier is calculated to be 0.53 eV (2.35 µm), which makes the absorption range of InAsSb cover an entire range from short-wavelength infrared to long-wavelength infrared spectrum. The fabricated photodetector exhibits a narrow response range from 2.0 µm to 2.3 µm with a peak around 2.1 µm at 300 K. The peak responsivity is 0.4 A/W under −500-mV applied bias voltage, corresponding to a peak quantum efficiency of 23.8% in the case without any anti-reflection coating. At 300 K, the photodetector exhibits a dark current density of 6.05×10 −3 A/cm 2 under −400-mV applied bias voltage and 3.25×10 −5 A/cm 2 under zero, separately. The peak detectivity is 6.91×10 10 cm•Hz 1/2 /W under zero bias voltage at 300 K.

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