Investigation of optoelectronic properties of GaAs/ AlxGa1-xAs qauntum well infrared photodetectors

In this thesis, electrical and optical properties of structures consist of asymetric GaAs/ AlxGa1-xAs multi-quantum wells grown by molecular beam epitaxy system were investigated. The structures were formed in device form by using photolitography process. To investigate electrical properties, temperature dependent dark current-voltage characteristics were experimentally measured. The dark current-voltage characteristics of the structures formed by asymmetric quantum wells were exhibited asymmetric behavior. Dark current depending on thermionic emission was also calculated by using Levine Model, 3D Carrier Drift Model and Emission Capture Model. When experimental results and calculated results were compared it was seen that the best fitting on the experimental results was found to be Levine Model. The ground state energy levels of each structure were calculated by using Kronig- Penney Model. Within the scope of investigation optical properties of the structures, temperature dependent photoluminescence measurements were taken.