[19p-P03-1~3] 15.3 III-V-group epitaxial crystals, Fundamentals of epitaxy

[19p-P03-1] First-Principles Study of Optical Absorption Due to Band Tail States in GaPN Alloys

〇Hiroyuki Yaguchi¹ (1.Saitama Univ.)

Keywords:GaPN alloy, first-principles calculation, optical absorption

In GaPN alloys, up-conversion luminescence is observed to result from two-step optical absorption via band tail states, which is expected to improve the energy conversion efficiency of photovoltaic cells. In this study, the electronic structure, electron density distribution and absorption coefficient of GaPN alloys were derived using full potential ab-initio calculations. The spectral weight approach was used to unfold the electronic structure derived from the supercells for the discussion about the characteristics of the band structure. The first-principles calculations revealed that the band gap energy of GaPN alloys significantly varies depending on the position of nitrogen atoms in spite of the same average concentration. I will present the calculated results about optical absorption due to band tail states and discuss the comparison with experimental results.