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

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 th e dependence of the linear pressure coefficient of the photoluminescence pe ak energy on Si doping in the barriers and excitation intensity. A nonlinea r increase of the piezoelectric field with hydrostatic pressure determined from these experiments is explained as being due to a significant dependenc e of the InGaN piezoelectric constants with strain. (C) 2001 American Insti tute of Physics.