AVS 50th International Symposium
    Electronic Materials and Devices Tuesday Sessions
       Session EM+SC-TuP

Paper EM+SC-TuP15
Effects of Threading Dislocations and In Composition on Structural and Optical Properties in InGaN/GaN Triangular-shaped Quantum Wells

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: R.J. Choi, Chonbuk National University, Korea
Authors: R.J. Choi, Chonbuk National University, Korea
Y.B. Hahn, Chonbuk National University, Korea
H.J. Lee, Chonbuk National University, Korea
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Structural and optical properties of InGaN/GaN multiple triangular quantum well (QW) structures have been studied with different threading dislocation (TD) densities and wavelengths (or In compositions). As the In composition increased, the extent of variation of the linewidth of photoluminescence (PL) measurements increased over a temperature range of 13 - 300 K. The structural quality of the quantum wells is not consistent with the PL intensity. More fluctuation of the local In composition and severer degradation of PL intensity at a higher TD density were observed, which were attributed to the stress field created by the dislocations. Observations by X-ray diffraction, transmission electron microscopy, and monochromated scanning cathodoluminescence imaging revealed that the optical property of the InGaN/GaN triangular-shaped MQWs is greatly affected by structural imperfections.