Photofacilitated Controllable Growth of ZnO Films Using Photoassisted Metal Organic Chemical Vapor Deposition
Photofacilitated Controllable Growth of ZnO Films Using Photoassisted Metal Organic Chemical Vapor Deposition
复制标题
利用光辅助金属有机化学气相沉积实现 ZnO 薄膜的光辅助可控生长
DOI：
10.1021/cg300609f
复制
发表时间：
2012-09-01
影响因子：
3.8
通讯作者：
Du, Guotong
中科院分区：
文献类型：
--
作者：
Shi, Zhifeng;Wu, Bin;Du, Guotong
采用光助金属-有机化学气相沉积(PA-MOCVD)系统在蓝宝石衬底上制备了高质量的氧化锌薄膜。观察到了具有不同结晶度的可控形貌演变。随着光照强度的增加，薄膜的微观结构由三维纳米棒形态转变为二维连续致密形态。提出了一种具有较高成核率和密度的可能的光促进成核机制，解释了形成的氧化锌的变化。在这种情况下，还对外延氧化锌的结晶度和光学性质进行了优化，从而可以获得与单晶氧化锌相似的低全宽半高(0.079度)摇摆曲线。实验还发现，通过增加光照射提供的热能和高能光子，可以有效地缓解薄膜的拉伸应变。此外，表现为强激子效应的随温度变化的光致发光结果证实了所获得的氧化锌薄膜的质量相对较好。
High-quality ZnO thin films were deposited on sapphire substrates using a photoassisted metal-organic chemical vapor deposition (PA-MOCVD) system. A controllable morphology evolution with varying degrees of crystallinity was observed. The microstructure of the film changes from a three-dimensional nanorod form to two-dimensional continuous dense form as the light irradiation intensity increases. A possible photofacilitated nucleation mechanism with a higher nucleation rate and density was proposed to explain the variation of the resulting ZnO formation. In this case, the crystallinity and optical properties of the epitaxial ZnO were also optimized, such that a low full width at half-maximum (0.079 degrees) of the rocking curve could be obtained, similar to that of single-crystal ZnO. It was also found that the tensile strain in the films could be availably relaxed by added thermal energy and energetic photons provided by light irradiation. Additionally, temperature-dependent photoluminescence results behaving as strong exciton effects confirmed the relatively excellent quality of the obtained ZnO films.