Theoretical study of orientation dependence of piezoelectric effects in wurtzite strained GaInN/GaN heterostructures and quantum wells

We calculated the crystal orientation dependence of piezoelectric fields in wurtzite strained Ga0.5In0.1N/GaN heterostructures. The highest longitudinal piezoelectric field of 0.7 MV/cm can be generated in (0001)-oriented biaxial-strained Ga0.5In0.1N layer coherently grown on GaN. On the contrary, no longitudinal piezoelectric field is induced in strained layers grown along orientations at an off angle of 39 degrees or 90 degrees from (0001). The high symmetry planes with these angles are, for instance, (11(2)over bar4) and (10(1)over bar2) for 39 degrees, and (11(2)over bar0) and (10(1)over bar0) for 90 degrees. We also calculated the crystal orientation dependence of the transition probability in a 3-nm strained Ga0.5In0.1N/GaN quantum well, which indicated that the transition probability with these non(0001) orientations becomes 2.3 times larger than that with the (0001) orientation. We conclude that high-performance strained nitride-based optical devices can be obtained by control of the crystal orientation.