摘要(英) |
The oxygen concentrations of ZnSe1-xOx alloys studied in this thesis are in the range of 1.5%x11.6%. Because of the limited oxygen solubility, Nabetani had proposed that ZnSeO alloy composition up to 6.4%. Our highest concentration up to 11.6%.In our previous study indicate the results of photoluminescence (PL) indicate that the relationship between band gap and oxygen composition can be well described in the framework of band anti-crossing model (BAC model). However, the full width of half maxima (FWHM) of signals becomes broader and the intensities become weaker in the higher O concentration range. These results indicate that the crystal structures may have changed. Thus we investigated the crystal structure via Raman spectrum.
In 10K Raman scattering experiments, the phonon frequency is influenced by strain and effective mass. With ZnSe mixes O, the phonon frequency become slower than ZnSe, but when oxygen concentration higher than 9.3%, the frequency is dominated by effective mass. The phonon frequency becomes faster.
In temperature-dependent Raman scattering, we can find as the oxygen concentration increases, the anharmonic effect will increase. Besides, the FWHM of LOZnSe becomes broader than ZnSe. In the end, we will discuss optical phonon life time. When increasing the oxygen concentration, the life time will become shorter than ZnSe. |
參考文獻 |
[1]Y. Nabetani, T. Mukawa, T. Okuno, Y. Ito, T. Kato, T. Matsumoto, Materials Science in Semiconductor Processing 6 (2003) 343–346
[2]J. C. Phillips, Bonds and Bands in Semiconductors (Academic, New York, 1973)
[3]W. Shan et al., Appl. Phys. Lett. 83, 299 (2003)
[4]W. Shan et al., Phys. Rev. Lett. 82, 1221 (1999)
[5]J. Wu et al., Semicond. Sci. Technol. 17, 860 (2002)
[6]J. Wu et al.,Phys. Rev. B 65, 233210 (2002)
[7]Kasimayan Uma, Cheng-Yu Chen, Chih-Kang Chao,Chih-Hung Wu, and Jen-Inn Chyi, Journal of Applied Physics 108, 103113 (2010)
[8]柯宏憲,氧硒化鋅合金的拉曼光譜研究,國立中央大學 物理學系 碩士論文
[9]Sadao Adachi, Properties of Semiconductor Alloys: Group-IV, III-V and II-VI Semiconductors, p. 99
[10]Balkanski,R. F. Wallis,and E. Haro, Phys. Rev. B, vol28, no.4,(1983)
[11]D. N. Talwar*,M. Vandevyver, K. Kunc and M. Zigone. Phys. Rev. B, vol24, no.2,(1981)
[12]H. Ibach, Phys.Stat. Sol.(b)33,257(1969)
[13]Thomas P. Pearsall, Strained-Layer Superlattices:Physics .Chaper 2
[14]C. V. Raman and K. S. Krishnan, “A new type of secondary radiation”, Nature (London) 121, 501-502 (1928)
[15]P. G. Klemens, “anharmonic decay of optical phonons” Phys. Rev. 148,845(1966)
[16]H. F. Liu and N. Xiang, S. Tripathy and S. J. Chua,” Raman scattering probe of anharmonic effects due to temperature and compositional disorder in GaNxAs1−x” Journal of Applied Phyics 99, (2006)
[17]Suruchi Anand, Prabhat Verma, K.P. Jain, S.C. Abbi, ”Temperature dependence of optical phonon lifetimes in ZnSe”, Physica B 226 (1996) 331-337
[18]K. Hayashi et al, Jpn. J. Appl. Phys. 30, 501 (1991)
[19]B. Hennion et al, Phys. Lett. 36A, 376 (1971) |