【作者】 袁波；

【导师】 郑学军；

【作者基本信息】 湘潭大学 ， 微电子学与固体电子学， 2011， 硕士

【摘要】 性能在微纳级器件方面具有潜在的应用而引起人们广泛的关注。目前,人们已经制备出了如纳米纤维、纳米带、纳米线和纳米棒等多种纳米结构,并发现它们具有如量子尺寸效应、表面效应和介电限域效应等新奇特性。ZnO和ZnS纳米材料是直接带隙半导体,均为六角纤锌矿结构,室温下的禁带宽度分别为3.37和3.68eV。由于尺寸效应和表面效应,ZnO和ZnS纳米材料具有某些独特的性能,如良好的光电、压敏等性能成为近年来的研究热点。本文介绍了制备ZnO单根纳米带光敏传感器及ZnO/ZnS纳米带膜的压敏传感器。在不同光照条件下测试了ZnO单根纳米带光敏传感器的伏安特性及其响应;在大气和不同的真空压强氛围下测试了基于ZnO/ZnS纳米带膜的压敏传感器的伏安特性;结合能带示意图,用氧吸附与解吸附理论对它们的实验机理进行了合理的解释。本文的主要内容包括以下几个方面:(1)采用磁控溅射和光刻的方法在SiO2/Si基底上制作Pt叉指电极,通过调节分散液的浓度并利用探针技术将单根ZnO纳米带组装在了叉指电极上,做成光敏传感器。用半导体参数测试仪及示波器测试了光敏传感器的伏安特性及响应,结果表明:在黑暗状态下,光敏传感器的关断性能较好;在波长范围为280~340nm的紫外光照射下,波长越短,光敏传感器的光电流和灵敏度越大。在紫外光打开和关闭交替变换时,光敏传感器实现了对电路状态“0”和“1”转换的控制。(2)将含有ZnO和ZnS纳米带的丙酮溶液旋涂在制备好的电极上组装出ZnO和ZnS带膜的真空压强敏感器件(压敏传感器)。用安捷伦4156C半导体参数测试仪测量这两种压敏传感器的伏安特性。结果表明:两种压敏传感器在黑暗条件下都处于高阻状态,随着大气压强的减小,传感器的电流增大。由伏安特性曲线得到的R-P曲线呈线性变化,可以根据电阻值的大小来判断传感器所处环境压强的大小。压敏传感器的测试范围从高真空到大气压强范围内。(3)利用光电导效应和表体比结合氧吸附与解吸附理论对ZnO单根纳米带光敏传感器的伏安特性及响应的变化规律进行了合理的解释。利用表体比和长的传输路径结合氧吸附与解吸附理论对基于ZnO和ZnS纳米带膜的压敏传感器伏安特性变化规律进行了合理的解释。更多还原

【Abstract】 With the development of device micromation, integration, and intellengence, nanostructures have attracted considerable attention due to their novel physics and chemistry characteristics for the potential applications in micro- and nano-devices. Many complex nanostructrues, such as nanofibers, nanobelts, nanowires and nanorods have been reported and the size effect, surface effect and dielectric confinement effect have been also explored. ZnO and ZnS nano materials are direct band gap semiconductor,and both of them are hexagonal wurtzite structure with the forbidden gap energy of 3.37 and 3.68 eV at room temperature. Due to the size effect and surface effect, ZnO and ZnS nanomaterials with some novel properties, such as excellent photosensitive and pressure-sensitive properties, become the hot topic in recent years. In this dissertation, the photo-sensitive and pressure-sensitive sensors based on ZnO single nanobelt, ZnO and ZnS nanobelts film were fabricated. For the former sensor the current-voltage (I-V) characteristics and response were measured under different illumination conditions, and for the latter sensors they were tested in air and under different vacuum pressure. The experimental results were explained by oxygen chemisorption and desorption mechanism combining with the schematic diagram of energy band. The main contents of the paper are given as follows.(1)Pt interdigital electrodes were fabricated on SiO2/Si substrate by using radio frequency magnetron sputtering and photolithography method. By controlling the concentration of mixed solution and using the probe technique, ZnO single nanobelt was set up on the interdigital electrodes, and the photo-sensitive sensor was fabricated. I-V characteristics of the photo-sensitive sensor were measured by semiconductor parameters tester and oscillograph. The results show that the photo-sensitive sensor has well shut off performance in darkness. Within the wavelength range of 280-340 nm, the shorter the wavelength is, the higher photocurrent and the larger photosensitivity are. As the UV-light turns“on”and“off”, the circuit state can be reversibly controlled by photosensitive sensor conversion between“0”and“1”.(2)The acetone solution containing ZnO and ZnS nanobelts were spined on the planar interdigital electrodes to assemble the vacuum pressure-sensitive sensor. I-V characteristics of the prepared pressure-sensitive sensor based on ZnO and ZnS nanobelts film were measured by Agilent 4156C semiconductor parameters tester. The results show that both pressure-sensitive sensors are of high impedance in darkness. With the decrease of the atmospheric pressure, sensor current increases. Resistance-pressure curves got from I-V characteristics curves vary linearly with the vacuum pressure change, the pressure of surrounding environment can be judged according to the changed resistance. The sensitivity range of pressure-sensitive sensor is comparative broad, and the vacuum to atmospheric pressure response is realized.(3)The I-V characteristics and time response of photo-sensitive sensor based on ZnO single nanobelt is reasonably explained by using the photoconductive effect and surface to volume ratio combine with oxygen absorption and desorption theory. I-V characters of the pressure-sensitive sensor based on ZnO and ZnS nanobelts film are explained by using the surface to volume ratio and long transmission path in conjunction with oxygen absorption and desorption theory.更多还原