[14p-PB12-1~23] 15.4 III-V-group nitride crystals

[14p-PB12-4] First-principles calculations of lattice constants, elastic constants, piezoelectric constants, and spontaneous polarization in wurtzite In_xAl_1-xN

〇Kazuhiro Shimada¹, Daichi Ito¹, Iwasaki Katsunori¹, Shigefusa Chichibu² (1.Kanto Gakuin Univ., 2.IMRAM-Tohoku Univ.)

Keywords:InAlN alloys,first-principles calculation

We performed first-principles calculations to obtain elastic constants, piezoelectric constants, and spontaneous polarization of wurtite In_xAl_1-xN in the basis of density fuctional theory. The atomic configuration in the unit cell was determined by the special quasi-random structure (SQS) method. Superlattice (SL) structures of (InN)_m(AlN)_n were also prepared for comparison. Similar results to the previous work were obtained for the elastic constants with the SQS atomic configurations except C₃₃, and those with SL structure also exhibited similar trende with the previous report, indicating that the atomic configuration affects the composition dependence of the elastic constans in wurtite In_xAl_1-xN. It was also predicted that the atomic configuration affected the composition dependence of the piezoelectric constans and spontaneous polarization.