GaAs-Alo 3Gao 7As kuantum çukurları sistemlerinde düzlemsel fotoiletkenlik
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Date
1991-01-18
Authors
Ergün, Yüksel
Journal Title
Journal ISSN
Volume Title
Publisher
Uludağ Üniversitesi
Abstract
Bu çalışmada iki ayrı GaAs-Al Ga As kuantum çukurları sistemleri fotoiletkenlik tekniği ile incelenmiştir. Elektrik alan, kuantum çukurlarının büyütülme eksenine dik doğrultuda uygulanmıştır. Monokromatik ışık altında elde edilen spektrumlarda gözlenen eksitonik geçişler, yapılan hesaplamalarla anlaşılmaya çalışılmış ve bandlaşma etkisi Kronig-Penney modeliyle incelenmiştir. Alçak sıcaklıklarda (T<100 K) yapılan deneylerde kalıcı fotoiletkenlik her iki kuantum çukurları sistemlerinde gözlenmiştir. Son olarak örneklerden biri için fon (background) ışığı ile fotoiletkenlik deneyleri tekrarlanmış ve gözlenen "defekt" seviyesinden ortaya çıkan fotoiletkenlik maksimumu anlaşılmaya çalışılmıştır.
In this study, two different GaAs-Al 0.3 Ga 0.7 quantum well struktures have been investigated by in-plane photoconductivity tecniquo. Different electric fields and light Intensities arc used to understand the electronic behavior of the structures. The low temperature (T<100 K) experiments show that that persistent photoconductivity is dominant. For photon energie slightly below the band gap of GaAs we find a sharp defect state at the same experimental condition. Electron and hole quantum states are calculated by using Bastard's k.p solution for single quantum well and Kronig-Penney model is used to understand subband effects for higher band to band exel tonic transitions. Light hole and electron nonparobolicities are included in both models.Dependence on background illumination intensities of whole photoconductivity spectrum show that, defect states are acceptor states.
In this study, two different GaAs-Al 0.3 Ga 0.7 quantum well struktures have been investigated by in-plane photoconductivity tecniquo. Different electric fields and light Intensities arc used to understand the electronic behavior of the structures. The low temperature (T<100 K) experiments show that that persistent photoconductivity is dominant. For photon energie slightly below the band gap of GaAs we find a sharp defect state at the same experimental condition. Electron and hole quantum states are calculated by using Bastard's k.p solution for single quantum well and Kronig-Penney model is used to understand subband effects for higher band to band exel tonic transitions. Light hole and electron nonparobolicities are included in both models.Dependence on background illumination intensities of whole photoconductivity spectrum show that, defect states are acceptor states.
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Keywords
Fotoiletkenlik, Quantum well, Photoconductivity, Kuantum kuyusu
Citation
Ergün, Y. (1991). GaAs-Alo 3Gao 7As kuantum çukurları sistemlerinde düzlemsel fotoiletkenlik. Yayınlanmamış doktora tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.