J4 ›› 2010, Vol. 27 ›› Issue (5): 620-625.

• Semiconductor Opto-electronics • Previous Articles     Next Articles

Improved theory of calculating mixed crystals phonon frequencies based on MREI model

LUO Fei1,  ZHENG Ruisheng2,  LU Min1, LIU Weiqing1   

  1. 1 Science College of Jiangxi University of Science and Technology,  Ganzhou 341000, China;
    2 Institute of Optoelectronics Shenzhen University,  Shengzhen 518060, China
  • Received:2009-11-12 Revised:2010-01-06 Published:2010-09-28 Online:2010-08-31

Abstract:

Based on the modified random-element isodisplacement (MREI) model, the theory is improved. The different second neighbor force constants are used to calculating the frequencies of optical phonons of the mixed crystals,and the first neighbor force constants can be evaluated to be a negative exponent variation with the composition x, thus the relationship between optical phonons frequencies and composition x of several AB1-xCx style mixed crystals has been calculated without any modulatory parameters. The theoretical results and the experimental datas meet well with each other, which give certain guidance to future experiments.

Key words: optoelectronics, MREI model, mixed crystals, optical phonon, composition