Abstract:

The optical property of zinc blend structure GaN under different highpressures was investigated by means of the plane wave pseudo-potential method with generalized gradient approximation. The results show the indirect band gap and the direct band gap widened with pressure increasing. GaN changed from direct band gap to indirect band gap semiconductor when ambient pressure reaches 125GPa.　Also, there was a blue shift at absorption wavelength with increasing pressure.

Key words: density functional theory; zinc blende structure; density ofstates