Growth and characterisation of semipolar group-III-nitride semiconductor materials

InGaN multiple quantum well (MQW) light emitting devices grown in the commonly used [0001] c-direction suffer piezoelectric and spontaneous polarization fields.These fields lead to the quantum confined stark effect(QCSE) , which causes a reduction of the radiative recombination efficiency. For certain semi-polar surfaces, e.g. (20-21) and (11-22),  a strong reduction of the polarization fields and thus the QCSE can be obtained. Despite  of  the  excellent  performance  of  green  laser diodes  on  (20-21)  GaN  with  emission wavelengths up to 530 nm, not much is known about growth dynamics and structural properties such as indium incorporation, surface reconstructions and critical layer thickness.

I will present TUB team activities in MOVPE growth and characterisation of semipolar InGaN and AlGaN. The talk is focused on the difficulties using standard characterisation techniques, like XRD and optical methods, and the different growth dynamics and strain relaxation mechanism in semipolar and polar nitrides.