InGaN/GaN blue light emitting diodes using Al-doped ZnO grown by atomic layer deposition as a current spreading layer

• Published in: Journal of crystal growth 2011-07, Vol.326 (1), p.147-151
• Main Authors: Kong, Bo Hyun, Cho, Hyung Koun, Kim, Mi Yang, Choi, Rak Jun, Kim, Bae Kyun
• Format: Article
• Language: English
• Subjects: A1. Doping; A3. Atomic layer epitaxy; Aluminum; Applied sciences; Azo; B1. Nitrides; B2. Semiconducting III–V materials; B2. Semiconducting II–VI materials; B3. Light emitting diodes; Cross-disciplinary physics: materials science; rheology; Deposition; Electronics; Emission; Exact sciences and technology; Gallium nitrides; Growth from vapor; Indium gallium nitrides; Light-emitting diodes; Materials science; Methods of crystal growth; physics of crystal growth; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Spreading; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2011.01.085

For the fabrication of InGaN/GaN multiple quantum well-based blue light emitting diodes (LEDs) showing large area emission, transparent Al-doped ZnO (AZO) films grown by atomic layer deposition at relatively low temperatures were introduced as current spreading layers. These AZO films with an Al content of 3 at% showed a low electrical resistivity of 10 20 cm −3, and an excellent optical transmittance of ∼85%, in spite of the low growth temperature. The deposition of the AZO film induced an intense blue emission from the whole surface of the p-GaN and weak ultraviolet emission from the n-AZO and p-GaN junction. At an injection current of 50 mA, the output powers of the blue LEDs were 1760 and 1440 mcd for the samples with AZO thicknesses of 100 and 300 nm, respectively.