| In the past decade, Quantum Dots Infrared Photodetectors (QDIPs) are playing an increasingly important role in diverse application fields, such as night vision, thermal imaging, remote sensing and space exploration. But their performances are still restricted by the relatively low quantum efficiency (QE) of ∼1%--3% due to the limitation on the active thickness. In this thesis, a normal-incidence, long-wavelength infrared (LWIR) QDIP with 20 periods of InAs-InGaAs quantum dots layers is demonstrated and discussed in details. A high quantum efficiency of 11.7% is obtained under the operating temperature of 78K with a bias of -4.8V. QDIPs with higher QE are expected by repeating more quantum dots layers, which allow a better sensitivity to MWIR (mid-wavelength infrared) and LWIR radiations. |
