Abstract SrTiO3 is cubic at room temperature, and retains cubic until the phase transition to tetragonal at 105K (-168oC). It is a wide-band-gap semiconductor having an energy gap Eg ≈ 3.0 eV, when its semiconductivity is greatly improved by doping with donor oxides, e.g.Nb2O5 or heat treatment in low oxygen partial pressures (Po2). Donor oxides in solid solution with SrTiO3 forming substitutional defects create electron or cation vacancies as the principal charge compensation defect. In-gap levels are also modified by the oxygen partial pressure (Po2) adopted in sintering, which generates oxygen vacancies in order to maintain the overall charge neutrality in the ceramic. In this research, donor-doping and Po2 used in sintering are investigated for the in-gap-level modification using the cathodoluminescence (CL) spectrometry equipped with a scanning electron microscope (SEM). Other analytical techniques, e.g. transmission electron microscopy (TEM) will be used for characterizing the defect structure. Preliminary results suggest that the in-gap levels are registered at 3.10 eV and 2.69 eV, representing the intrinsic Eg and a donor-level created by oxygen vacancies, respectively.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0806110-143433 |
| Date | 06 August 2010 |
| Creators | Chen, Ting-Yu |
| Contributors | Wei-Lin Wang, Hong-Yang Lu, Bing-Hwai Hwang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0806110-143433 |
| Rights | withheld, Copyright information available at source archive |
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