镧掺杂对CdO－SnO_2系物相及性能的影响

在ＣｄＯ－ＳｎＯ＿２体系中加入Ｌａ￣（３＋）可以提高学钛铁矿型β－ＣｄＳｎＯ＿３的热稳定性。通过对掺镧材料的物相及微结构的研究、认为Ｌａ￣（３＋）部分固溶到β－ＣｄＳｎＯ＿３品格中是提高其稳定性的主要原因。并可控制掺镧方式及热处理温度来合成不同相组成的气敏材料，改善ＣｄＯ－ＳｎＯ＿２系的气敏性能。     

掺镉纳米SnO2的热稳定性,电导及气敏性能

本文研究了ＣｄＯ掺杂对纳米ＳｎＯ２粉料的热稳定性，电导及气敏特性的影响。结果表明，以非晶状态均匀分散在ＳｎＯ２颗粒表面的ＣｄＯ能阻止ＳｎＯ２之间的相互扩散，提高了纳米ＳｎＯ２的热稳定性；固溶于ＳｎＯ２昌粒中的ＣｄＯ量（Ｃｄ／Ｓｎ〈０．０５）很小，但对元件的电导影响显著；纳米级的晶粒尺寸（〈６ｎｍ）及ＣｄＯ的掺杂大大改善了ＳｎＯ２的气敏特性。     

CuO－SnO_2半导体陶瓷气敏机理研究

本文根据实验结果，分析了以ＳｎＯ＿２为主体材料的ＣｕＯ作添加剂的ＣｕＯ－ＳｎＯ＿２气敏传感器的敏感性能，并从理论上对其气敏机理进行了探讨。     

镧掺杂对CdO—SnO2系物相及性能的影响

在ＣｄＯ－ＳｎＯ２体系中加入Ｌａ＆３＋可以提高钛铁矿型β－ＣｄＳｎＯ３的热稳定性。通过对掺镧材料的物相及微结构的研究，认为Ｌａ＾２＋部分固溶到β－ＣｄＳｎＯ２晶格中要提高其稳定性的主要原因。并可控制掺镧方式及热处理温度来合成不同相组成的气敏材料，改善ＣｄＯ－ＳｎＯ２系的气敏性能。     

多功能NiO—SnO2气敏材料的敏感特性

采用化学共淀淀法合成了不同配比的ＮｉＯ－ＳｎＯ２气敏材料，用Ｘ射线衍射法分析材料的结构与组成，测试了元件的气敏性能，并利用表面催化作用较好的解释了材料的敏感机理，通过改变ＮｉＯ的掺杂量及气敏元件的加热功率，ＮｉＯ－ＳｎＯ２材料可分别实现对Ｈ２，Ｃ２Ｈ５ＯＨ的选择性检测以及对Ｃ２Ｈ５ＯＨ、Ｈ２、ＣＯ、Ｃ４Ｈ１０和汽油等气体的广谱检测。     

Sol—Gel法制备ZrO2—SnO2薄膜的常温气敏机理

根据Ｓｏｌ－Ｇｅｌ工艺制备的ＺｒＯ２－ＳｎＯ２薄膜的气敏性能数据，提出了常温下ＳｎＯ２（ＺｒＯ２）薄膜对Ｈ２Ｓ的气敏机理模型。根据此模型所得定量分析结果与实验结果一致。     

微结构气敏传感器敏感薄膜制备方法的研究

随着微结构气敏传感器的出现,金属氧化物半导体薄膜因具有灵敏度高、热质量小、批量制备一致性好等特点受到日益广泛的重视,本比较了在微结构气敏传感器中三种方法制备的ＳｎＯ２敏感薄膜的结构和气敏响应特性。结果表明,用液涎生长和热氧化技术制备Ｓｎ２薄膜虽然能采用Ｌｉｆｔ－ｏｆｆ技术成形,但由于膜中晶粒结构和Ｓｎ／Ｏ比不合适使得它的气敏响应特性很差;室温混合气氛（Ａｒ／Ｏ２比为８：２）下射频溅射ＳｎＯ２靶然     

多孔SnO2薄膜的导电和气敏特性

用ＲＧＴＯ方法制备多孔，颗粒状ＳｎＯ薄膜；根据ＳＥＭ观察结果建立简单导电模型，并验证其导电机制主要是晶界导电；研究纯ＳｎＯ２薄膜及掺杂ＳｎＯ２薄地ＣＯ，乙醇等气体的气敏特性，掺Ｐｔ的薄对ＣＯ有很好的气敏响应；选择合适工作温度，可提高灵敏度改善选择性。     

SnO2超细粉体应用于低温气敏材料

采用超临界流体干燥技术制备了纳米级ＳｎＯ２粉体。通过简单的掺杂，测试了其对ＣＯ、Ｈ２气敏效果，使其检测温度分别降至３０℃和１２０℃左右。同时，通过对元件成型温度的考察，使其烧结温度比传统ＳｎＯ２元件下降１００￣２００℃。从而肯定了超细ＳｎＯ２可以大大节省能耗，适用于低温气敏材料。     

ZrO2掺杂对SnO2薄膜电性及气敏性的影响

本研究不用金属醇盐而以无机盐ＳｎＣｌ２．２Ｈ２Ｏ为主体原料，以Ｚｒ（ＯＣ３Ｈ７）４为掺杂剂，无水乙醇为溶剂，采用溶胶－疑胶Ｓｏｌ－Ｇｅｌ）工艺制备了不同ＺｒＯ２掺杂份量的ＳｎＯ２薄膜，发现ＺｒＯ２薄膜在常温下对Ｈ２Ｓ气体具有较好的气敏性能，同时本文研究了ＺｒＯ２掺杂份量对ＳｎＯ２薄膜导电率及气敏性能的影响。     

MO—PECVD SnO2—x气敏薄膜

以金属有机化合物(MO)四甲基锡[sn(CH_3)_4]为源物质,利用等离子体增强化学气相沉积技术,分别在单晶硅片、三氧化二铝陶瓷基片上淀积了纯净的SnO_(2-x)薄膜,对淀积的一些工艺条件,膜的结构、成分和薄膜元件的气敏性能进行了研究,并与普通PECVDSnO_(2-x)薄膜元件的气敏性能作了比较,对SnO_(2-x)膜的气敏机理作了探讨。     

ZnO/SnO_2,SnO_2/ZnO UPF复合膜的制备及气敏特性研究

用直流气体放电活化反应蒸发沉积技术在普通玻璃基片上制备了ZnO／SnO2及SnO2／ZnO超微粒子（UPF）双层复合薄膜。样品经扫描电子显微镜（SEM）和X射线衍射仪分析，结论为超微粒子的复合薄膜。同时提出了最佳制备工艺。气敏测试结果表明：ZnO／SnO2及SnO2／ZnOUPF复合膜较单层ZnO及SnO2UPF表现出优良的选择性，其灵敏度和最佳工作温度也得到相应的改善。     

多层气敏薄膜表面吸附及界面扩散的研究

制备了ＳｎＯ３／ＺｎＯ及ＺｎＯ／ＳｎＯ３多层结构的气敏薄膜，用能谱结合氩离子刻蚀的方法及Ｘ射线衍射法，对薄膜的表面吸附。膜间的相互与组成等进行了研究，结果表明：薄膜表面存在少量的吸附多层膜中锌的扩散远比锡一个模型，对吸附现象作了初步的解释，讨论了造成锌锡扩散的原因。     

SnO2-x薄膜非化学计量比对气敏性能的影响

采用反应磁控溅射法制备SnO2薄膜经常出现化学计量比的失衡问题。通过控制溅射过程中的氧分压制备不同化学计量比的SnO2-x薄膜,研究非化学计量比对薄膜结构、成分以及气敏性能的影响。XRD结果表明氧分压对材料结构和取向的影响非常显著。薄膜的O／Sn和表面化学成分通过XPS进行确定,分析发现氧分压的增加促使薄膜接近化学计量比,但表面化学吸附氧含量在0．33Pa氧分压下达到最大。气敏性能测试表明,非化学计量比主要影响薄膜表面的化学吸附氧数量,从而影响导电性和气体敏感性。氧分压对薄膜化学吸附氧的影响趋势与对气敏性能的影响趋势一致。0．33Pa氧分压下制备的薄膜拥有最多的表面吸附氧,同时对氢气的灵敏度高达45．6％。另外,在0．2～0．5Pa氧分压下制备的薄膜对氢气具有较好的选择性。     

Structural and gas sensing behavior of nanocrystalline BaTiO3 based liquid petroleum gas sensors

In this paper nanosized BaTiO₃ thick films based gas sensor has been fabricated for liquid petroleum gas (LPG). Doping with different concentrations of metal oxides influenced the sensitivity of BaTiO₃ thick films for LPG sensor. We present the characterization of both their structural properties by means of X-ray powder diffraction (XRD) and the electrical characteristics by using gas-sensing properties. X-ray powder diffraction analyses revealed the persistence of cubic phase with grain growth 65 nm. The LPG-sensing properties of BaTiO₃ thick films doped with CuO and CdO are investigated. It was found that 10 wt.% CuO: 10 wt.% CdO doped BaTiO₃ based LPG sensor shows better sensitivity and selectivity at an operating temperature 250 °C which is an important commercial range for LPG alarm development. Incorporation of 0.3 wt.% Pd doped CuO:CdO:BaTiO₃ element shows maximum sensitivity with high cross selectivity to the other gases including CO, H₂ and H₂S at an operating temperature 225 °C for low concentrations of LPG sensor.     

Synthesis and characterization of CdO-doped nanocrystalline ZnO:TiO2-based H2S gas sensor

This paper reports the preparation and gas-sensing characteristic of ZnO:TiO₂-based hydrogen sulfide (H₂S) gas sensor with different mol% of CdO by polymerized complex method. The structural and gas-sensing properties of ZnO:TiO₂ materials have been characterized using X-ray diffraction and gas-sensing measurement. The electrical resistance response of the sensor based on the materials was investigated at different operating temperatures and different gas concentrations. The sensor with 10 mol% CdO-doped ZnO:TiO₂ shows excellent electrical resistance response toward H₂S gas. The cross sensitivity was also checked for reducing gases like CH₄, CO and H₂ gas. The selectivity and sensitivity of ZnO:TiO₂-based H₂S gas sensor were improved by the addition of 10 mol% of CdO at an operating temperature of 250 °C.     

稀土Dy掺杂纳米SnO_2薄膜的结构与气敏特性

采用真空蒸发法在玻璃衬底上制备稀土Dy掺杂Sn薄膜,对薄膜进行合适的氧化、热处理后获得Dy掺杂SnO2薄膜.用X射线衍射、场发射扫描电子显微镜、静态配气法对薄膜性能进行测试,研究不同掺Dy含量和热处理条件对SnO2薄膜的影响.结果显示,制备的SnO2薄膜呈金红石结构为n型;在相同热处理条件下,Dy掺杂可明显缩短薄膜氧化、热处理的时间;适当掺入稀土Dy可明显改善SnO2薄膜的结构、气敏特性.掺Dy 3at%后可大大提高SnO2薄膜对丙酮气体的灵敏度.     

Structural, optical and electrical measurements on boron-doped CdO thin films

Several boron-doped CdO with different boron composition thin films have been prepared on glass substrate by a vacuum evaporation technique. The effects of boron doping on the structural, electrical and optical properties of the host CdO films were systematically studied. The X-ray diffraction study shows that some of B³⁺ ions occupied locations in interstitial positions and/or Cd²⁺-ion vacancies of CdO lattice. The band gap of B-doped CdO suffers narrowing by 30–38% compare to undoped CdO. Such band gap narrowing (BGN) was studied in the framework of the available models. Furthermore, a phenomenological evaluation of the dependence of band gap on the carrier concentration in the film samples is discussed. The electrical behaviours show that all the prepared B-doped CdO films are degenerate semiconductors. However, the boron doping influences all the optoelectrical properties of CdO. Their dc-conductivity, carrier concentration and mobility increase compare to undoped CdO film. The largest mobility of 45–47 cm²/V s was measured for 6–8% boron-doped CdO film. From near infrared transparent-conducting oxide (NIR-TCO) point of view, boron is effective for CdO donor doping.     

Influence of Yb-doping on optoelectrical properties of CdO nanocrystalline films

Yb-doped CdO thin films with different Yb contents were prepared on glass and silicon substrates by vacuum evaporation technique. The effects of Yb-doping on the structural and optoelectrical properties of the host CdO films were systematically studied. The X-ray diffraction study shows that some of Yb³⁺ ions substituted for Cd²⁺ and the solubility of Yb in CdO is very limited and may be around ~0.2 at.%. The Yb-doping influences all the optoelectrical properties of CdO. The bandgap of Yb-doped CdO suffers narrowing by about 20% with a very small (0.03 at.%) doping level. The electrical behaviours show that all the prepared Yb-doped CdO films are degenerate semiconductors. Their dc-conductivity, carrier concentration, and mobility increase compared with undoped CdO film. The largest mobility of about 87 cm²/V s was measured for 0.13 at.% Yb-doped CdO film. From transparent-conducting-oxide point of view, Yb is sufficiently effective for CdO-doping.