Epitaxial growth and optical properties of ZnTe/ZnMgSe QDs

• Main Authors: Huang, Shih-Han, 黃詩涵
• Other Authors: Chou, Wu-Ching
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/02604612516367078840

碩士 === 國立交通大學 === 電子物理系所 === 102 === ZnTe quantum dots (QDs) were grown on Zn1-xMgxSe by molecular beam epitaxy using the Stranski Krastanov (SK) growth mode. The photoluminescence (PL), power dependent PL and time-resolved PL spectra were used to investigate the interesting physical properties. The tuning of the lattice mismatch by varying Mg concentration was demonstrated in the ZnTe/ Zn1-xMgxSe QDs. The critical thickness of wetting layer was estimated by the observation of abrupt change of photoluminescence (PL) emission energy with the ZnTe coverage. Two different red-shift slopes are observed for the PL peak energy. The peak energy of low temperature PL decreases promptly when the ZnTe coverage is less than the critical thickness and gently when the ZnTe coverage exceeds critical thickness. The PL bands blue-shift as excitation power increases. The decay profiles could be well fitted by two components lifetime. The long decay time measured from TRPL and PL bands blue-shift with increasing excitation power confirm that the ZnTe/ Zn1-xMgxSe QDs has a type II band alignment.