Two-color ingaasn/gaas/algaas quantum well photodetector

• Main Author: Naw, Sandar Win
• Other Authors: Fan Weijun
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/61404
• Institution: Nanyang Technological University

The purpose of this project is to design a two-color InGaAsN/GaAs/AlGaAs quantum well intersubband transition photodetector using k.p method to calculate the energy levels and absorption. The radiation detection ranges for the two wavelengths are 3-5 μm (target: 4 μm) and 8-10 μm (target: 10 μm) using material InGaAsN/GaAs/AlGaAs step quantum wells. Two-color quantum well photodetectors have become potential demanding which are incorporated with commercial applications over traditional thermal detectors since QWIPs have advantages in fast response time, high impedance, and low power consumption. In quantum well photodetector, the electrons will be elevated from the quantum well to the barrier due to photon absorption. When the well width is sufficiently small, the motion of electrons in the well is quantized in the growth direction and the energy levels in this direction become discrete. Parameters like quantum well width and barrier widths are varied to obtain the desired wavelengths. In this project, barrier AlGaAs is set to 100Å, while other variables such as InGaAsN well width and, GaAs, barrier width, In(x) and N(y)InxGa1-xAs1-yNy] will have to adjust to get the target wavelengths.