TY - GEN
T1 - Analysis of light extraction efficiency enhancement for InGaN quantum wells light-emitting diodes with microspheres
AU - Zhao, Peng
AU - Jiao, Xuechen
AU - Zhao, Hongping
PY - 2012/11/12
Y1 - 2012/11/12
N2 -
The enhancement of light extraction efficiency for thin-film flip-chip (TFFC) InGaN quantum wells (QWs) light-emitting diodes (LEDs) with self-assembled microspheres on top of the n-GaN layer was studied. The light extraction efficiency of InGaN QWs LEDs for the three structures with 1) close-packed SiO
2
microlens; 2) close-packed SiO
2
/ polystyrene microlens; and 3) GaN micro-hemispheres were calculated and compared to that of the conventional InGaN QWs LEDs with flat surface. Three dimensional finite difference time domain (3D-FDTD) method was used to calculate the light extraction efficiency for TFFC InGaN/GaN QWs LEDs emitting at 460nm. The effects of the microsphere/micro-hemisphere diameter and the p-GaN layer thickness on the light extraction efficiency were studied. Studies show that the p-GaN layer thickness is critical for optimizing the TFFC LED light extraction efficiency. Light extraction efficiency enhancement of 1.7 times and 1.85 times were obtained in the TFFC LEDs with SiO
2
microlens and SiO
2
/polystyrene microlens, respectively. More significant enhancement of the light extraction efficiency (>2.6 times) was achieved from LEDs with GaN micro-hemispheres with optimized micro-hemisphere diameter of D=1μm and p-GaN thickness of 195nm.
AB -
The enhancement of light extraction efficiency for thin-film flip-chip (TFFC) InGaN quantum wells (QWs) light-emitting diodes (LEDs) with self-assembled microspheres on top of the n-GaN layer was studied. The light extraction efficiency of InGaN QWs LEDs for the three structures with 1) close-packed SiO
2
microlens; 2) close-packed SiO
2
/ polystyrene microlens; and 3) GaN micro-hemispheres were calculated and compared to that of the conventional InGaN QWs LEDs with flat surface. Three dimensional finite difference time domain (3D-FDTD) method was used to calculate the light extraction efficiency for TFFC InGaN/GaN QWs LEDs emitting at 460nm. The effects of the microsphere/micro-hemisphere diameter and the p-GaN layer thickness on the light extraction efficiency were studied. Studies show that the p-GaN layer thickness is critical for optimizing the TFFC LED light extraction efficiency. Light extraction efficiency enhancement of 1.7 times and 1.85 times were obtained in the TFFC LEDs with SiO
2
microlens and SiO
2
/polystyrene microlens, respectively. More significant enhancement of the light extraction efficiency (>2.6 times) was achieved from LEDs with GaN micro-hemispheres with optimized micro-hemisphere diameter of D=1μm and p-GaN thickness of 195nm.
KW - finite difference time domain
KW - InGaN quantum wells
KW - light extraction efficiency
KW - Light-emitting diodes
KW - self-assembled microspheres
KW - thin-film flip-chip (TFFC)
UR - http://www.scopus.com/inward/record.url?scp=84868563516&partnerID=8YFLogxK
U2 - 10.1109/EnergyTech.2012.6304699
DO - 10.1109/EnergyTech.2012.6304699
M3 - Conference Paper
AN - SCOPUS:84868563516
SN - 9781467318365
T3 - 2012 IEEE Energytech, Energytech 2012
BT - 2012 IEEE Energytech, Energytech 2012
T2 - 2012 IEEE Energytech, Energytech 2012
Y2 - 29 May 2012 through 31 May 2012
ER -