发光学报, 2014, 35 (5): 526, 网络出版: 2014-05-06
Ⅱ-Ⅵ比对分子束外延生长的ZnO/ZnMgO超晶格的相结构调控
Phase Segregation of ZnO/ZnMgO Superlattice Affected by Ⅱ-Ⅵ Ratio
摘要
在Zn1-xMgxO中, x=0.4~0.6仍为一个岩盐矿和纤锌矿共存的结构, 影响了其晶格质量。本文利用等离子体辅助的分子束外延设备在c面蓝宝石衬底上外延生长了ZnO/ZnMgO超晶格, 并改变其生长过程中的Ⅱ-Ⅵ比, 利用原子力显微镜、X射线衍射、透射谱和X射线光电子能谱对样品进行了表征分析。发现在较低氧分压下制备的样品结构以岩盐矿为主导, 而在较高氧分压下两相共存并以纤锌矿为主。这种相分离现象与裂解氧原子的密度有关。
Abstract
ZnMgO alloy allows for tunable optoelectronic devices. However, the compositional range between ZnO and MgO is interrupted by a crystalline miscibility gap where the wurtzite crystal structure of ZnO is structurally incompatible with the rocksalt structure of MgO. In this article, ten periods of ZnO/ZnMgO superlattice were produced by plasma-assistant molecular beam epitaxy on c-plane sapphire substrate with different oxygen condition. It is found that the sample grown at lower oxygen flow and radio-frenquency (RF) plasma power tends to form rocksalt phase. With the increase of oxygen flow and RF plasma power, wurtzite phase tends to dominate and phase segregation is enhanced. The phase transform affected by the oxygen atoms density is reasoned by the formation enthalpies of ZnO and MgO.
王浩, 詹华瀚, 陈晓航, 周颖慧, 王惠琼, 康俊勇. Ⅱ-Ⅵ比对分子束外延生长的ZnO/ZnMgO超晶格的相结构调控[J]. 发光学报, 2014, 35(5): 526. WANG Hao, ZHAN Hua-han, CHEN Xiao-hang, ZHOU Ying-hui, WANG Hui-qiong, KANG Jun-yong. Phase Segregation of ZnO/ZnMgO Superlattice Affected by Ⅱ-Ⅵ Ratio[J]. Chinese Journal of Luminescence, 2014, 35(5): 526.