Fabrication and characterization of devices based on III-V group semiconductors

In this study, multi-quantum well resonant cavity Ga0.66In 0.34N0.018As0.982/GaAs and Ga0.733In0.267N0.025As0.975/GaN0.035As0.965 SACM photodetector structrues which are sensitive to 1.3 µm wavelength have been investigated. The active region of the detector is consists of Ga1-xIn xN1-yAsy. Barrier layer is GaAs and GaNyAs1-y. Photodetector structures consist of 9 quantum wells, 10 top and 15 bottom "Distributed Bragg Reflectors" (DBRs). These values were determined depending on materials of active region and barrier as well as alloy concentrations of these materials. In the modeling process of the photodetector structures, Band Anti-Crossing Model and Vegard's Law were utilized for calculations of active region and barrier materials. On the other hand, SimWindows has been used for internal electric field distributions and DBR structures that provide resonance cavity were calculated using Transfer Matrix Method (TMM). Photodetector structures were grown by the Tampere University of Technology Optoelectronics Research Center (Finland) using the Molecular Beam Epitaxy (MBE) Magnification method were fabricated as mesa structure with a diameter of 125 - 650 µm by using facilities of Advanced Lithography Laboratories/Istanbul University Science Faculty Physics Department. Electronic and Optical characterizations were also carried out using the facilities of Nano and Optoelectronics Research Laboratory within the same research laboratories. Dark current, responsivity and quantum efficiencies of the photodetectors were obtained by current-voltage and photocurrent measurements at room temperature. Resonant cavity 9 QWs Ga0.66In 0.34N0.018As0.982/GaAs SACM photodetector structure, the quantum efficiency was calculated as maximum value at 1274 nm and responsivity was calculated as 13 mA/W. The FWHM has been determined at 5 nm. The quantum efficiency (QE) of %1.34 has been achieved at -1 V. Resonant cavity 9 QWs Ga0.733In0.267N0.025As0.975/GaN0.035As0.965 SACM photodetector structure, the quantum efficiency was calculated as maximum value at 1282 nm and responsivity was calculated as 64 mA/W. The FWHM has been determined at 5 nm. The quantum efficiency (QE) of %6.27 has been achieved at -1 V. Resonant cavity 9 QWs Ga0.733In0.267N0.025As0.975/GaN0.035As0.965 p-i-n photodetector structure, the quantum efficiency was calculated as maximum value at 1296 nm and responsivity was calculated as 8 mA/W. The FWHM has been determined at 5 nm. The quantum efficiency (QE) of %0.79 has been achieved at 0 V. All obtained results are presented by comparing with the literature.