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Full-Text Articles in Physical Sciences and Mathematics
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 …