Eight-Band K.P Calculations of InAs/GaAs Pyramid Shape Quantum Dots Using FDM for Far Infrared 8-12 μm Windows

Infrared (IR) detection (3-12 μm), especially in 8-12 μm has many applications in commercial, military, night vision, thermal imaging, non destructive detection and missile remote control. Because of large carrier life time in Quantum Dot Infrared Photodetectors (QDIP), they have lower dark current and higher responsivity in larger temperature relative to Quantum Well Infrared Photodetectors (QWIP), and especially can absorb normal incidence light where QWIP cannot [1-5].In the earlier works [6], a single QD structure, with an especial shape, has been analyzed with or without band mixing and eigenenergies have been determined. In this paper, we study the mid and far infrared wavelength absorption through the conduction subbands, in quantum dots. We solve the effective mass Schrödinger equation with cubic and pyramid shape quantum dot structures using Finite Difference Method (FDM). Then we utilize 8-band K.P method for pyramid shape InAs/GaAs QD and determine the base size of dot for peak absorption wavelengths in the range of 8-12 μm.