Polarization Fields In Semipolar (20(1)Over-Bar(1)Over-Bar) And (20(2)Over-Bar1) Ingan Light Emitting Diodes

InxGa1-xN/GaN multiple quantum well structures (x = 0.13 and 0.18) embedded into p-i-n diodes on (20 (2) over bar(1) over bar) and (20 (2) over bar1) oriented GaN substrates were investigated by electroreflectance, photocurrent, and electroluminescence. Transition energies in absorption and emission experiments were measured as a function of the polarization orientation of light and applied bias voltage. The results were analyzed by a perturbation theoretical model to determine polarization fields. For the (20 (2) over bar(1) over bar) sample (x = 0.18), the flatband voltage is found at thorn1V corresponding to a polarization field of -458 kV/cm. For the (20 (2) over bar(1) over bar) sample (x = 0.13), the polarization field is estimated to be approximate to+330 kV/cm at flatband voltage higher than turn-on voltage of this light emitting diode. Published under license by AIP Publishing.