Optical Characterization of ZnBeMnSe Mixed Crystal
碩士 === 國立臺灣科技大學 === 電子工程系 === 95 === This paper deals with the investigation of temperature dependence of the near band-edge transitions of a series of diluted magnetic semiconductor Zn0.95-xBe0.05MnxSe mixed crystals using contactless electroreflectance (CER) , photoreflectance (PR) and photolumine...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
2007
|
| Online Access: | http://ndltd.ncl.edu.tw/handle/46871740363942927952 |
| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 95 === This paper deals with the investigation of temperature dependence of the near band-edge transitions of a series of diluted magnetic semiconductor Zn0.95-xBe0.05MnxSe mixed crystals using contactless electroreflectance (CER) , photoreflectance (PR) and photoluminescence(PL) and Surface Photovoltage Spectroscopy (SPS) in the temperature range of 15 to 400 K. The crystals were grown by the modified high pressure Bridgman method from the melt for 0.05 < x < 0.2. Room-temperature SPS has been used as a diagnostic technique for checking the surface condition of the sample. Typical PL spectrum at low temperature consists of free exciton line, an edge emission due to recombination of shallow donor-acceptor pairs, and the emission transition 4T1 (4G) →6A1 (6S) in Mn2+ ion at cation lattice site. The CER spectrum reflects the energetic distribution of states. So the near band edge transition energies are determined by analyzing the CER spectra. The peak positions of the exciton emission lines in the PL spectra correspond quite well to the energies of the fundamental transition determined by SPS and CER data. The parameters that describe the temperature dependence of the transition energy and broadening parameter of the fundamental band-edge exciton have been evaluated and discussed.
|
|---|