GaN薄膜的两步法制备及其物性转变的研究

摘要

The GaOOH film composed of spindle-shaped GaOOH microparticles was firstly fabricated by hydrothermal method on Si substrate spun with ZnO particles, and then ammoniated at 950 ℃ by CVD method to give GaN film. The morphologies, crystal structure and optical properties of the samples before and after ammoniation were characterized by FESEM, EDS, TEM, XR.D and PL analyses. The results show that the GaOOH film was composed of spindle-shaped microrods with a diameter of 600 nm and a length of about 1.5 ～2 μm. Ammoniation did not change the morphologies of GaOOH film but converted its crystal structure from orthorhombic phase of GaOOH into wurtzite GaN; and the position of PL peak at the green light range for GOOH films shifted to blue range with a peak at 365 nm, which may be related to the transformation of crystal structure. Finally, the formation mechanism of GaOOH film and the chemical reaction during the transformation from GaOOH film to GaN film were proposed.%本实验通过水浴加热和简单化学气相氨化两步法,在旋涂有ZnO的Si衬底上成功合成了由排列整齐纺锤体形貌的GaOOH构成的薄膜,然后在950 ℃下对样品进行氨化得到由排列整齐纺锤体组成的GaN薄膜.然后对氨化前后样品的形貌,结构和光学性能分别通过FESEM、EDS、TEM、XRD和PL谱进行了表征.结果表明:水热生成的GaOOH薄膜是由纺锤体形状GaOOH紧密排列形成,该纺锤体形状GaOOH有直径大约600 nm,长约为1.5～2 μm.氨化前后样品的形貌没发生太大的变化;但晶体结构由正交晶系相GaOOH转变为六方纤锌矿GaN;而且发光峰也由较宽的绿光峰转变为中心为365 nm的蓝光峰,这主要是由于样品由正交晶系相GaOOH转变为六方纤锌矿GaN引起的.最后对排列整齐的锤体形构成的GaOOH薄膜的形成机理以及GaOOH向GaN的转变过程发生的化学反应做了简单的探讨和分析.