Browsing by Author "Liao, Wei-Tsai"

Now showing 1 - 3 of 3

Optical properties of (1 (1)over-bar 0 1) semi-polar InGaN/GaN multiple quantum wells grown on patterned silicon substrates
(2011-03-01)
Chiu, Ching-Hsueh
;
Lin, Da-Wei
;
Lin, Chien-Chung
;
Li, Zhen-Yu
;
Chen, Yi-Chen
We present a study of high quality (1 (1) over bar 0 1) GaN films and the InGaN/GaN multiple quantum wells (MQWs) using epitaxial lateral overgrowth (ELO) technique by atmospheric pressure metal organic chemical vapor deposition (MOCVD). The smooth coalescence of the stripes and surface morphology was measured by scanning electron microscope (SEM) and atomic force microscopy (AFM). Due to reduction in internal electric field, semipolar InGaN/GaN MQWs have higher radiative recombination rate from time-resolved photoluminescence (TRPL) measurement. In addition, from degree of polarization (DOP) measurement, we observed higher polarization ratio attributed to the induced anisotropic compressive strain. (C) 2010 Published by Elsevier B.V.
Reduction of Efficiency Droop in Semipolar (1(1)over-bar01) InGaN/GaN Light Emitting Diodes Grown on Patterned Silicon Substrates
(2011-01-01)
Chiu, Ching-Hsueh
;
Lin, Da-Wei
;
Lin, Chien-Chung
;
Li, Zhen-Yu
;
Chang, Wei-Ting
We present a study of semi-polar (1 (1) over bar 01) InGaN-based light emitting diodes (LEDs) grown on patterned (001) Si substrates by atmospheric-pressure metal organic chemical vapor deposition. A transmission electron microscopy image of the semi-polar template shows that the threading dislocation density was decreased significantly. From electroluminescence measurement, semi-polar LEDs exhibit little blue-shift and low efficiency droop at a high injection current because the reduction of the polarization field not only made the band diagram smoother but also restricted electron overflow to the p-GaN layer as shown in simulations. These results indicate that semi-polar InGaN-based LEDs can possess a high radiative recombination rate and low efficiency droop at a high injection current. (C) 2011 The Japan Society of Applied Physics
Reduction of Efficiency Droop in Semipolar (1(1)over-bar01) InGaN/GaN Light Emitting Diodes Grown on Patterned Silicon Substrates (vol 4, 012105, 2011)
(2011-03-01)
Chiu, Ching-Hsueh
;
Lin, Da-Wei
;
Lin, Chien-Chung
;
Li, Zhen-Yu
;
Chang, Wei-Ting