Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 45: GaN devices

HL 45.3: Vortrag

Donnerstag, 28. Februar 2008, 10:00–10:15, EW 202

Semipolar {1101} GaInN quantum wells for green light emitting diodes — •Martin Feneberg¹, Thomas Wunderer², Frank Lipski², Peter Brückner², Ferdinand Scholz², Rolf Sauer¹, and Klaus Thonke¹ — ¹Institut für Halbleiterphysik, Universität Ulm — ²Institut für Optoelektronik, Universität Ulm

Semipolar GaInN/GaN light emitting devices are a heavily discussed topic in current research. These devices are supposed to help filling the so-called "green gap" of wavelengths between 500nm and 600nm where no efficient emitters exist.

Semipolar {1101} quantum wells were grown, processed and finally analyzed by electric-field-dependent photoluminescence and electroluminescence. From the PL emission energy as a function of the externally applied voltage which modifies the built-in polarization field we have determined the remaining polarization field. For this purpose, model calculations were carried out which self-consistently take full account of the tilted band structure, charge accumulation, fields in the depletion region and other relevant parameters. With these results we are able to calculate the internal quantum efficiencies of semipolar quantum wells. After carefully adjusting growth and process parameters while maintaining material quality we demonstrate first semipolar light emitting diodes operating at about 500nm.