Dominant role of the piezoelectric field in the pressure behavior of InGaN/GaN quantum wells

Abstract

We show that the emission characteristics of InGaN/GaN quantum wells under hydrostatic pressure are strongly influenced by the built-in piezoelectric field. The dominant role of the piezoelectric field is established from the dramatic increase of the photoluminescence decay time with pressure and the dependence of the linear pressure coefficient of the photoluminescence peak energy on Si doping in the barriers and excitation intensity. A nonlinear increase of the piezoelectric field with hydrostatic pressure determined from these experiments is explained as being due to a significant dependence of the InGaN piezoelectric constants with strain.