Gryshchenko S. Spectral properties of semiconductor multi-layered photodetector based on GaAs/InGaAs and GaN/alGaN materials with microresonator

Thesis for a doctor philosophy degree (Ph.D.) in physical-mathematical sciences by according to scientific specialty 01.04.05 - optics, laser physics - V.N. Karazin Kharkiv national university, Kharkiv, 2014 In dissertation the theoretical description and research of quantum efficiency of semiconductor resonance photodetektor (RFD) is presented. Dependences of quantum efficiency form top mirror reflectivity were got at the different parameters of structure. The values of the top mirror reflectivity are found depending on the physical parameters of structure. Use of microcavity, built-in in a top mirror allowed to get the quantum efficiency flat-top in the RFD. With the use of method of harmonic oscillators dependence the spectrums of reflection and quantum efficiency of the temperature of RP substrate has been investigated. By a mathematical model based on the solving of Schr?dinger of and Blokh equations the dipole transitions matrix elements and spectrum of absorption of quantum-cascade photodetector are investigated. It is showed that subband filling effect has significantly influence on absorption of radiation in quantum-cascade photodetectors. The method of diminishing of influence of this effect is offered due to the use of optical resonator with high good quality. Modeling of absorption in quantum-cascade RFD on the basis of nitride compounds shows lowering influence of this effect by 80%. Keywords - Quantum efficiency, reflection, absorption spectrum, subband filling effect, resonance photodetector, quantum-cascade photodetector, distributed Bragg reflector.