Structure and optical properties of ternary alloy BeZnO and quaternary alloy BeMgZnO films growth by molecular beam epitaxy

详细信息    查看全文

• 作者：Longxing Su^a ; ^{sulx@mail2.sysu.edu.cn} ; Yuan Zhu^a ; ^c ; ^{zhuy9@mail.sysu.edu.cn} ; Quanlin Zhang^a ; Mingming Chen^a ; Tianzhun Wu^a ; Xuchun Gui^a ; Bicai Pan^b ; Rong Xiang^a ; Zikang Tang^a ; ^c ; ^{phzktang@ust.hk}
• 关键词：BeZnO ; BeMgZnO ; Crystal quality ; Band-gap ; MSM detector
• 刊名：Applied Surface Science
• 出版年：2013
• 出版时间：1 June, 2013
• 年：2013
• 卷：274
• 期：Complete
• 页码：341-344
• 全文大小：1237 K

文摘

Ternary alloy BeZnO and quaternary alloy BeMgZnO films were prepared on sapphire (0 0 1) substrate by radio-frequency plasma-assisted molecular beam epitaxy (RF-PAMBE). Based on X-ray diffraction (XRD) analysis, no phase segregation is observed for all the alloys. However, Be_xZn_1?xO alloys exhibit a constantly worse crystal quality than Be_xMg_yZn_1?x?yO alloys at the similar incorporation contents (i.e. x in BeZnO approximately equals to x + y in BeMgZnO). Optical transmittance spectra were recorded to determine the energy band gap of the films. BeMgZnO was revealed more effective in widening the band gap. Finally, BeZnO and BeMgZnO based MSM structure UV detectors were fabricated. BeMgZnO alloys with better crystal quality showed a favorable optical response and the cutoff wavelength shifted continuously to deep ultraviolet range, while BeZnO based detectors were found no response. This is the first report on BeMgZnO based UV detector, which is a meaningful step forward to the real application.