Quantum dot infrared photodetector enhanced by avalanche multiplication

A novel intersubband quantum dot photodetector is proposed and theoretically investigated. The presented device is based on the integration of a multiplication layer with a quantum dot infrared photodetector to increase generated photocurrent and enhance performance characteristics. To keep the dark current at lower values, resonant tunnelling barriers are used in absorption layers and designed so that there is photocurrent at a specific resonant wavelength. Numerical simulations show a higher responsivity of approximately 12 A/W and higher specific detectivity of approximately 6×10⁹ cm.Hz^1/2/W at λ=11 μm.