title: Growing GaN LEDs on amorphous SiC buffer with variable C/Si compositions.
abstract: The epitaxy of high-power gallium nitride (GaN) light-emitting diode (LED) on amorphous silicon carbide (a-SixC(1-x)) buffer is demonstrated. The a-SixC(1-x) buffers with different nonstoichiometric C/Si composition ratios are synthesized on SiO2/Si substrate by using a low-temperature plasma enhanced chemical vapor deposition. The GaN LEDs on different SixC(1-x) buffers exhibit different EL and C-V characteristics because of the extended strain induced interfacial defects. The EL power decays when increasing the Si content of SixC(1-x) buffer. The C-rich SixC(1-x) favors the GaN epitaxy and enables the strain relaxation to suppress the probability of Auger recombination. When the SixC(1-x) buffer changes from Si-rich to C-rich condition, the EL peak wavelengh shifts from 446 nm to 450 nm. Moreover, the uniform distribution contour of EL intensity spreads between the anode and the cathode because the traping density of the interfacial defect gradually reduces. In comparison with the GaN LED grown on Si-rich SixC(1-x) buffer, the device deposited on C-rich SixC(1-x) buffer shows a lower turn-on voltage, a higher output power, an external quantum efficiency, and an efficiency droop of 2.48 V, 106 mW, 42.3%, and 7%, respectively.
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University (NTU), No.1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Cheng
authors.affiliation: Department of Electrophysics, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan, R.O.C.|Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan.
authors.forename: An-Jye
authors.initials: AJ
authors.lastname: Tzou
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University (NTU), No.1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Jung-Hung
authors.initials: JH
authors.lastname: Chang
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University (NTU), No.1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Yu-Chieh
authors.initials: YC
authors.lastname: Chi
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University (NTU), No.1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Yung-Hsiang
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan.|Research Center for Applied Sciences, Academia Sinica, Taipei 115 Taiwan.
authors.forename: Min-Hsiung
authors.initials: MH
authors.lastname: Shih
authors.affiliation: Department of Photonics and Department of Physics, National Sun Yat-sen University, No. 70, Lien-Hai Rd., Kaohsiung 804, Taiwan.
authors.forename: Chao-Kuei
authors.initials: CK
authors.lastname: Lee
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University (NTU), No.1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Chih-I
authors.initials: CI
authors.lastname: Wu
authors.affiliation: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan.
authors.forename: Hao-Chung
authors.initials: HC
authors.lastname: Kuo
authors.affiliation: Department of Electrophysics, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan, R.O.C.|Department of Electronics Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Chang
authors.affiliation: Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University (NTU), No.1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan R.O.C.
authors.forename: Gong-Ru
authors.initials: GR
authors.lastname: Lin