Properties of Semipolar GaInN/GaN Light Emitting Diodes on Selectively Grown GaN Stripes

Semipolar GaInN/GaN light emitting diodes (LEDs) were investigated as possible candidates for high-brightness devices even in the long wavelength regime. To combine the high material quality known from c-GaN and the advantage of a reduced piezoelectric field, the LED structures were realized on the {1101} side facets of selectively grown GaN stripes that have a triangular shape. Time-resolved and locally resolved photoluminescence (PL) measurements show drastically reduced lifetimes for the semipolar sample of only 650 ps at 4K whereas we found lifetimes exceeding 50 ns for a polar reference sample. Furthermore, more than a doubling of the PL intensity and a significantly reduced blue shift of the peak wavelength with increasing excitation power provides further evidence for the presence of reduced piezoelectric fields in the semipolar sample. Bright blue light emission with powers as high as 700μW and 3mW could be achieved in electroluminescence measurements under dc conditions for 20 and 110mA, respectively.