Controlled Synthesis of AlN/GaN Multiple Quantum Well Nanowire Structures and Their Optical Properties

详细信息    查看全文

• 作者：Fang Qian ; Megan Brewster ; Sung K. Lim ; Yichuan Ling ; Christopher Greene ; Oleg Laboutin ; Jerry W. Johnson ; Silvija Grade膷ak ; Yu Cao ; Yat Li
• 刊名：Nano Letters
• 出版年：2012
• 出版时间：June 13, 2012
• 年：2012
• 卷：12
• 期：6
• 页码：3344-3350
• 全文大小：390K
• 年卷期：v.12,no.6(June 13, 2012)
• ISSN：1530-6992

文摘

We report the controlled synthesis of AlN/GaN multi-quantum well (MQW) radial nanowire heterostructures by metal鈥搊rganic chemical vapor deposition. The structure consists of a single-crystal GaN nanowire core and an epitaxially grown (AlN/GaN)_m (m = 3, 13) MQW shell. Optical excitation of individual MQW nanowires yielded strong, blue-shifted photoluminescence in the range 340鈥?60 nm, with respect to the GaN near band-edge emission at 368.8 nm. Cathodoluminescence analysis on the cross-sectional MQW nanowire samples showed that the blue-shifted ultraviolet luminescence originated from the GaN quantum wells, while the defect-associated yellow luminescence was emitted from the GaN core. Computational simulation provided a quantitative analysis of the mini-band energies in the AlN/GaN superlattices and suggested the observed blue-shifted emission corresponds to the interband transitions between the second subbands of GaN, as a result of quantum confinement and strain effect in these AlN/GaN MQW nanowire structures.

Keywords:

GaN; AlN; Nanowire Heterostructures; Multiple Quantum Wells; Cathodoluminscence; Photoluminescence