【作者】 韩舜；

【导师】 申德振； 张吉英； 张振中；

【作者基本信息】 中国科学院研究生院（长春光学精密机械与物理研究所） ， 凝聚态物理， 2011， 博士

【摘要】 MgZnO材料具有晶格匹配的衬底,无毒环保、带隙可调范围宽等优势,因此近年来MgZnO材料的制备及紫外探测器的研制成为了一个研究热点。本论文利用反应磁控溅射和金属有机物化学气相沉积方法（MOCVD）制备出六角和立方结构的MgZnO薄膜,并研究MgZnO薄膜的性质及其在紫外探测器件方面的应用。主要研究内容如下[1]利用反应多靶磁控溅射的方法,在石英和c面蓝宝石衬底上获得了单一六角取向Mg_0.53Zn_0.47O薄膜材料。并在所生长Mg_0.53Zn_0.47O薄膜上制备了可探测270-320nm紫外光的探测器件。并开展了不同衬底对Mg_0.53Zn_0.47O薄膜紫外光吸收和紫外光响应性质影响的研究。[2]用反应磁控溅射的方法,在石英衬底上制备了不同Mg组分的立方结构MgZnO薄膜,并研究薄膜的结晶及光学性质。优化生长条件,在不同面的蓝宝石衬底上制备了立方MgZnO薄膜。并且开展了不同退火温度对不同面蓝宝石衬底上立方MgZnO结晶质量,表面形貌,吸收光谱等性质的影响。[3]利用MOCVD的方法,在晶格匹配的单晶MgO衬底上,通过在生长MgZnO之前加入一层MgO缓冲层的方法,获得了高平整度的Mg_0.58Zn_0.42O单晶薄膜,并且在平整表面的Mg_0.58Zn_0.42O薄膜上制备了响应峰值在240nm,响应截止边在255nm的MSM结构日盲紫外探测器。开展了MgO缓冲层对立方MgZnO薄膜结晶质量、表面形貌、吸收光谱等性质影响的研究。通过优化生长条件,在MgO衬底上获得了高质量的单晶立方MgZnO薄膜。通过湿法刻蚀的方法在薄膜制备具有内增益的光导型太阳盲紫外探测器。当探测器工作在大于15V偏压时,器件对238nm紫外光的量子效率大于100%。[4]首次利用两步退火的方法制备了Au/Mg_0.27Zn_0.73O/In肖特基光伏型紫外探测器,器件在-5V偏压下可见光响应度比原生样品上制备的探测器小了近一个数量级。通过对两步退火方法对六角结构MgZnO薄膜表面形貌、光致发光等性质影响的研究揭示退火处理造成Au电极与MgZnO薄膜间接触特性变化的原因。更多还原

【Abstract】 MgZnO material has many advantages, such as: no Toxicity, no pollution to environment, wide band gap adjustable region, has lattice matched substrate , so in recent years the fabrication of MgZnO Materials and MgZnO based UV detectors has become a hotspot. In this thesis, hexagonal and cubic structure MgZnO thin films would be grown by reactive magnetron sputtering and metal organic chemical vapor deposition （MOCVD） methods, and the prorperties of MgZnO and its application in UV detectors would be studied. The main contents are as follows:[1] Hexagonal orientation Mg_0.53Zn_0.47O thin films were prepared on quartz and c-plane sapphire substrate by multi-target reactive magnetron sputtering method. And UV detectors with detectable wavelength range from 270-320nm were fabricated on prepared Mg_0.53Zn_0.47O thin films. The study on effect of different substrates on light absorption and UV response characteristics of MgZnO thin films was carried out.[2]Cubic structure MgZnO thin films with different Mg composition were prepared on fused quartz substrates by the method of reactive magnetron sputtering, the crystallization and optical properties of cubic MgZnO thin films were studied. Under optimal growth conditions, cubic MgZnO thin films were prepared on different plane sapphire substrates. The Effect of different annealing temperature on crystal quality, surface morphology, and absorption spectra properties of cubic MgZnO on different plane sapphire substrates was studied.[3] Through introducing a MgO buffer layer, slick surface Mg_0.58Zn_0.42O thin film on lattice matched single crystal MgO substrates by MOCVD method. And MSM structure solar-blind UV detector was fabricated on prepared high quality Mg_0.58Zn_0.42O with response peak at 240nm, cut-off response edge at 255nm. The effect of MgO buffer layer on crystal quality, surface morphology, absorption spectrum and other properties of cubic MgZnO thin films were studied. Under optimized growth conditions, high quality single crystal cubicMgZnO film was prepared on MgO substrate, and solar-blind photoconductive UV detector was fabricated on the MgZnO thin film By wet etching method with internal gain. At bias voltage over 15V bias, the quantum efficiency of the device at 238nm is more than 100%.[4] For the first time, Au/Mg_0.27Zn_0.73O/In Schottky photovoltaic detector was fabricated by a two-step anneal treatment method. Under -5V bias voltage, visible responsivity of the detector is about an order of magnitude smaller than the detector on as-grown MgZnO thin film. By surface morphology and photoluminescence measurements, the reason for the improvement of the contact characteristics between the Au electrode and the MgZnO is discussed.更多还原