Rational growth of semi-polar ZnO texture on a glass substrate for optoelectronic applications

• Published in: Journal of physics. D, Applied physics Applied physics, 2013-02, Vol.46 (5), p.55105-1-7
• Main Authors: Lu, B, Ma, M J, Ye, Y H, Lu, J G, He, H P, Ye, Z Z
• Format: Article
• Language: English
• Subjects: Applied sciences; Circuit properties; Diffusion rate; Doping; Electric, optical and optoelectronic circuits; Electronics; Evolutionary; Exact sciences and technology; Glass; Integrated optoelectronics. Optoelectronic circuits; Optical and optoelectronic circuits; Optoelectronic devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surface layer; Texture; Windows (intervals); Zinc oxide
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/46/5/055105

Semi-polar ZnO films with surface texture were grown on glass substrates via pulsed-laser deposition (PLD) through Co-Ga co-doping. Oxygen pressure (PO2) was found to have significant effects on the structural and optical properties of the Zn(Co, Ga)O (ZCGO) films. A self-textured film with preferred orientation (PO) was achieved by varying the growth conditions including a crucial narrow PO2 window and growth time. A possible mechanism underlying the PO evolution and the final texture of the films was proposed, which can be attributed to the collaboration of the doping effect and the PO2-dependent evolutionary selection process, in which certain grains can have increased vertical growth rate with respect to the substrate surface through interplane diffusion. Moreover, the growth of undoped pure ZnO films proceeded by using the ZCGO film as a buffer layer. The ZnO layers retained a semi-polar characteristic with improved crystallinity and better optical quality. The epitaxy-like orientation of ZnO layers grown on ZCGO films has applications in the development of semi-polar ZnO-based light-emitting diodes.