Mechanical and electronic properties under high pressure on ternary AlGaN and InGaN compounds—a first-principles perspective

The electronic and mechanical properties of AlGaN and InGaN were analyzed in the pressure range of 0 GPa to 50 GPa by the first-principles study. Moreover, the energy band structure gets modified upon increasing pressure. The density of states (DOS) spectrum of AlGaN and InGaN shows the shift in the peaks upon increase in the pressure. The elastic constants for rhombohedral AlGaN and InGaN were established. By estimating the Young's, bulk and shear moduli, an upsurge in the magnitude was observed with the intensifying pressure. The ductility of AlGaN and InGaN were demonstrated by examining the Poisson's ratio, Cauchy's pressure and Pugh's criterion under increasing the pressure. We observed increase in the ductility of AlGaN and InGaN upon applied pressure. Thus, the findings suggest that the band gap of AlGaN and InGaN can be fine-tuned on applying the pressure, which is suitable to fabricate new optoelectronic devices. (paper)