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Articles 1 - 5 of 5
Full-Text Articles in Physics
Influence Of Annealing On Photoelectric Characteristics And Stability Of Elements Based On Si-Bi$_{2}$Te$_{3-X}$Se$_{X}$, Gurban Ahmadov
Influence Of Annealing On Photoelectric Characteristics And Stability Of Elements Based On Si-Bi$_{2}$Te$_{3-X}$Se$_{X}$, Gurban Ahmadov
Turkish Journal of Physics
In the manufacture of Bi$_{2}$Te$_{3-x}$Se$_{x}$-based elements using two sources of the deposited substance, they were initially annealed at a temperature of 150-200 \textdegree Ñ in a low vacuum. Heat treatment led to a slight increase in short circuit current and an increase in open circuit voltage. When the elements were heated in high vacuum, as well as in atmospheres of argon, nitrogen, hydrogen, helium and other gases, irreversible changes in the characteristics were not detected. Heat treatment of elements at a temperature of 100--150 \textdegree C in oxygen always improves their performance. It is assumed that annealing stimulates the growth …
Analysis Of Gan/Alxga1?Xn Heterojunction Dual-Band Photodetectors Using Capacitance Profiling Techniques, Laura E. Byrum
Analysis Of Gan/Alxga1?Xn Heterojunction Dual-Band Photodetectors Using Capacitance Profiling Techniques, Laura E. Byrum
Physics and Astronomy Theses
Capacitance-voltage-frequency measurements on n+-GaN/AlxGa1−xN UV/IR dual-band detectors are reported. The presence of shallow Si-donor, deep Si-donor, and C-donor/N-vacancy defect states were found to significantly alter the electrical characteristics of the detectors. The barrier Al fraction was found to change the position of the interface defect states relative to the Fermi level. The sample with Al fraction of 0.1 shows a distinct capacitance-step and hysteresis, which is attributed to C-donor/N-vacancy electron trap states located above the Fermi level (200 meV) at the heterointerface; whereas, the sample with Al fraction of 0.026 shows negative capacitance and dispersion, indicating C-donor/N-vacancy and deep Si-donor …
Uncooled Infrared Photon Detection Concepts And Devices, Viraj Vishwakantha Jayaweera Piyankarage
Uncooled Infrared Photon Detection Concepts And Devices, Viraj Vishwakantha Jayaweera Piyankarage
Physics and Astronomy Dissertations
This work describes infrared (IR) photon detector techniques based on novel semiconductor device concepts and detector designs. The aim of the investigation was to examine alternative IR detection concepts with a view to resolve some of the issues of existing IR detectors such as operating temperature and response range. Systems were fabricated to demonstrate the following IR detection concepts and determine detector parameters: (i) Near-infrared (NIR) detection based on dye-sensitization of nanostructured semiconductors, (ii) Displacement currents in semiconductor quantum dots (QDs) embedded dielectric media, (iii) Split-off band transitions in GaAs/AlGaAs heterojunction interfacial workfunction internal photoemission (HEIWIP) detectors. A far-infrared detector …
Semiconductor Quantum Structures For Ultraviolet-To-Infrared Multi-Band Radiation Detection, Gamini Ariyawansa
Semiconductor Quantum Structures For Ultraviolet-To-Infrared Multi-Band Radiation Detection, Gamini Ariyawansa
Physics and Astronomy Dissertations
In this work, multi-band (multi-color) detector structures considering different semiconductor device concepts and architectures are presented. Results on detectors operating in ultraviolet-to-infrared regions (UV-to-IR) are discussed. Multi-band detectors are based on quantum dot (QD) structures; which include quantum-dots-in-a-well (DWELL), tunneling quantum dot infrared photodetectors (T-QDIPs), and bi-layer quantum dot infrared photodetectors (Bi-QDIPs); and homo-/heterojunction interfacial workfunction internal photoemission (HIWIP/HEIWIP) structures. QD-based detectors show multi-color characteristics in mid- and far-infrared (MIR/FIR) regions, where as HIWIP/HEIWIP detectors show responses in UV or near-infrared (NIR) regions, and MIR-to-FIR regions. In DWELL structures, InAs QDs are placed in an InGaAs/GaAs quantum well (QW) to …
Threshold Extension Of Gallium Arsenide/Aluminum Gallium Arsenide Terahertz Detectors And Switching In Heterostructures, Mohamed Buhary Rinzan
Threshold Extension Of Gallium Arsenide/Aluminum Gallium Arsenide Terahertz Detectors And Switching In Heterostructures, Mohamed Buhary Rinzan
Physics and Astronomy Dissertations
In this work, homojunction interfacial workfunction internal photoemission (HIWIP) detectors based on GaAs, and heterojunction interfacial workfunction internal photoemission (HEIWIP) detectors based mainly on the Gallium Arsenide/Aluminum Gallium Arsenide material system are presented. Design principles of HIWIP and HEIWIP detectors, such as free carrier absorption, photocarrier generation, photoemission, and responsivity, are discussed in detail. Results of p-type HIWIPs based on GaAs material are presented. Homojunction detectors based on p-type GaAs were found to limit their operating wavelength range. This is mainly due to band depletion arising through carrier transitions from the heavy/light hole bands to the split off band. Designing …