GaN/TiO2-x异质结的制备以及氮化温度对其光电化学性能的影响  

Preparation of GaN/TiO2-x Heterojunction and Effect of Nitriding Temperature on Its Photoelectrochemical Properties

作　　者：钱凯[1] 薛晋波[2] 胡兰青[1] QIAN Kai;XUE Jinbo;HU Lanqing(College of Materials Science and Engineering,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;Key Laboratory of Interface Science and Engineering in Advanced Materials,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]太原理工大学新材料界面科学与工程教育部重点实验室,太原030024

出　　处：《太原理工大学学报》2019年第5期549-555,共7页Journal of Taiyuan University of Technology

基　　金：国家自然科学基金资助项目(21878257,51402209,21276220);山西省自然科学基金资助项目(201601D102020,201701D221083);山西省重点研发计划项目(201603D121017,201803D421079,201803D31042);山西省高等学校科技创新项目(2016124);山西省科技创新重点研究团队(201605D131045-10);江苏省生态建材与环保装备协同创新中心暨江苏省新型环保重点实验室联合开放基金

摘　　要：采用溶胶凝胶法,以硝酸镓为镓源、二氧化钛纳米粉末为钛源,制备出Ga2O3/TiO2粉末材料。将样品置于不同温度下氮化,得到GaN/TiO2-x粉末。利用场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)、紫外-可见分光光度计(UV-Vis)、荧光分光光度计(PL)、表面光电压谱仪(SPV)、电化学工作站等对样品进行表征和性能测试,研究了氮化温度对样品的物相组成、微观形貌以及光电性能的影响。结果表明,氮化温度越高,Ga2O3被氮化的程度越高,GaN的结晶度越好。700℃下氮化时,TiO2保持原有状态,不发生相变和还原反应;当氮化温度达到750℃时,样品中的TiO2开始逐渐被还原为TiO2-x,且随着温度的升高,二氧化钛被还原的程度增大,TiO2-x量增多;从800℃开始,样品中几乎不含TiO2.紫外-可见光吸收数据显示,700℃氮化的样品吸收范围最大,900℃氮化的样品带隙最窄,而吸光度则大致随着氮化温度的升高而增大。电化学测试结果表明,850℃氮化的样品导电性最好,载流子浓度最高,且分离效率高,在-0.8V(vs.Ag/AgCl)偏压条件下,850℃和800℃氮化的样品瞬态光电流密度最高。Ga 2O 3/TiO 2 powder was prepared using gallium nitrate and titanium dioxide nanopowder by sol-gel method.The sample was nitrided at different temperatures to obtain GaN/TiO 2-x powder.Field emission scanning electron microscopy(FESEM),X-ray diffractometry(XRD),UV-Vis spectrophotometry(UV),fluorospectrophotometry(PL),surface photovoltage spectrometry(SPV),electrochemical measurement were used to investigate the effects of nitriding temperature on the phase composition,morphology and photoelectric properties of the samples.The results show that the higher the nitriding temperature,the higher the degree of nitriding of Ga 2O 3,and the better the crystallinity of GaN.When nitrided at 700℃,TiO 2 remained its original state with no phase change and reduction reaction;when nitriding temperature reached 750℃,TiO 2 in the sample began to be gradually reduced to TiO 2-x,and with the increase of temperature,the degree of reduction and the amount of TiO 2-x increased.Almost no TiO 2 was observed in the sample nitrided at temperature over 800℃.The UV-visible absorption data show that the absorption range of sample nitrided at 700℃was the widest,the band gap of the sample nitrided at 900℃was the narrowest,and the absorbance increased with the increase of nitridation temperature.Electrochemical test results show that the samples nitrided at 850℃had the best conductivity,the highest carrier concentration and the highest separation efficiency.At-0.8 V(vs.Ag/AgCl)bias,the photocurrent density of the sample nitrided at 850℃was the highest.

关 键 词：Ga2O3/TiO2 溶胶凝胶法 氮化温度 GaN/TiO2-x 光电化学性能 

分 类 号：O472[理学—半导体物理] O475[理学—物理]