MBE growth and characterization of THz detector structures using quantum confined impurity atoms

Detectors/emitters working at THz frequency region of the electromagnetic spectrum have very broad area of use. However, despite their great potential, detection systems operating in this region have not reached the sufficient maturity. To make up for this deficiency, THz detectors using the hydrogenic energy levels of the confined impurity atoms (1s, 2p±) located in a quantum well can be produced as an alternative approach to the existing systems. This thesis contains production and characterization of THz detecting systems based on dipole allowed transitions between the energy states (1s→2p) of the quantum confined impurity atoms. At first, the delta doping studies were done by using double barrier resonant tunneling and multiple quantum well structures. Photoluminescence (PL) measurements for multiple quantum well samples and dark current and voltage dependent photoluminescence measurements for double barrier resonant tunneling samples were conducted. Multiple quantum well structures were grown with previously determined parameters for the delta doping, and the absorption measurements in the far-infrared (FIR) region were performed. In these measurements, 1s→2p± transitions were observed in absorbance spectrum of p-type delta doped samples. Dark current, photocurrent and photo response characterizations have also been made for devices with lateral device design; however, no clear response was observed in the optical measurements.