Low-bias, high-temperature performance of a normal-incidence InAs/GaAs vertical quantum-dot infrared photodetector with a current-blocking barrier

The properties of a low-bias and high-temperature InAs/GaAs vertical quantum-dot infrared photodetector (QDIP) with a single Al0.3Ga0.7As current-blocking barrier were investigated. This device demonstrated high peak detectivity and a high operating temperature for normal-incidence vertical QDIPs. High-temperature operations in QDIPs resulted from a large electron relaxation time from the excited states to the ground state in quantum dots, allowing excited carriers to escape from the dot and contribute to the photocurrent before relaxing back into the ground state. The low bias performance of the photodetector ensured its compatibility with commercially available silicon read-out circuits.