Influence of Size of ZnO Nanorods on Light Extraction Enhancement of GaN-Based Light-Emitting Diodes
DAI Ke-Hui1,4**, WANG Lian-Shan2**, HUANG De-Xiu1, SOH Chew-Beng3, CHUA Soo-Jin3,4
1Wuhan National Laboratory for Optoelectronics, School of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 2College of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 3Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, Singapore 4Centre for Optoelectronics, Department of Electrical and Computer Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore
Influence of Size of ZnO Nanorods on Light Extraction Enhancement of GaN-Based Light-Emitting Diodes
DAI Ke-Hui1,4**, WANG Lian-Shan2**, HUANG De-Xiu1, SOH Chew-Beng3, CHUA Soo-Jin3,4
1Wuhan National Laboratory for Optoelectronics, School of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 2College of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 3Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, Singapore 4Centre for Optoelectronics, Department of Electrical and Computer Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore
摘要We investigate the influence of size of ZnO nanorods on the light extraction efficiency (LEE) enhancement of GaN-based light-emitting diodes (GaN-LEDs). ZnO nanorods with different sizes are hydrothermally grown on patterned indium-doped tin oxide (ITO) electrodes of the GaN-LEDs in zinc acetate aqueous solutions of different concentrations. Measurements are conducted for the LEE enhancement of the LEDs with ZnO nanorods, compared to these without ZnO nanorods. The results suggest that the LEE of the LEDs with ZnO nanorods increases with the increasing size of ZnO nanorods. However, a saturation trend for the LEE improvement is also observed, which is attributed to the maximum limitation of light coupled into ZnO nanorods from GaN-based LEDs, and the reflection is increased by the increasing top surface of the ZnO nanorods.
Abstract：We investigate the influence of size of ZnO nanorods on the light extraction efficiency (LEE) enhancement of GaN-based light-emitting diodes (GaN-LEDs). ZnO nanorods with different sizes are hydrothermally grown on patterned indium-doped tin oxide (ITO) electrodes of the GaN-LEDs in zinc acetate aqueous solutions of different concentrations. Measurements are conducted for the LEE enhancement of the LEDs with ZnO nanorods, compared to these without ZnO nanorods. The results suggest that the LEE of the LEDs with ZnO nanorods increases with the increasing size of ZnO nanorods. However, a saturation trend for the LEE improvement is also observed, which is attributed to the maximum limitation of light coupled into ZnO nanorods from GaN-based LEDs, and the reflection is increased by the increasing top surface of the ZnO nanorods.
[1] Horng R H, Yang C C, Wu J Y, Huang S H, Lee C E and Wuu D S, 2005 Appl. Phys. Lett. 86 221101
[2] McGroddy K, David A, Matioli E, Iza M, Nakamura S, DenBaars S, Speck J S, Weisbuch C and Hu E L 2008 Appl. Phys. Lett. 93 103502
[3] Ryu H Y and Shim J I 2010 IEEE J. Quantum Electron. 46 714
[4] Gao H, Yan F, Zhang Y, Li J, Zeng Y and Wang G 2008 J. Appl. Phys. 103 014314
[5] Chang C T, Hsiao S K, Chang E Y, Hsiao Y L, Huang J C, Lu C Y, Chang H C, Cheng K W and Lee C T 2009 IEEE Photon. Technol. Lett. 21 1366
[6] Kim H, Lee S N, Park Y, Kim K K, Kwak J S and Seong T Y 2008 J. Appl. Phys. 104 053111
[7] Jang D H, Shim J I and Shin D S 2009 IEEE Photon. Technol. Lett. 21 760
[8] Zhong J, Chen H, Saraf G, Lu Y, Choi C K, Song J J, Mackie D M and Shen H 2007 Appl. Phys. Lett. 90 203515
[9] An S J, Chae J H, Yi G C and Park G H 2008 Appl. Phys. Lett. 92 121108
[10] Kim K K, Lee S D, Kim H, Park J C, Lee S N, Park Y, Park S J and Kim S W 2009 Appl. Phys. Lett. 94 071118
[11] Dalui S, Lin C C, Lee H Y, Chao C H and Lee C T 2010 IEEE Photon. Technol. Lett. 22 1220
[12] Dai K, Soh C B, Jin C S, Wang L and Huang D 2011 J. Appl. Phys. 109 083110
[13] Peter K H H, Stephen D, Thomas, Friend R H and Tessler N 1999 Science 285 233
2011, Vol. 28 
