利用光电子能谱研究氧化锌压敏电阻界面电输运特性

采用X射线光电子能谱(XPS)对比分析纯氧化锌陶瓷和氧化锌压敏电阻的界面特性。结果表明,纯氧化锌陶瓷晶粒平均尺寸小于10 祄,掺杂材料有利于ZnO晶粒均匀生长。界面上O/Zn原子数量比值等于2.58,但界面势垒不到10 mV,其体电阻率在2.36~47.97佟m。价电子谱发现:室温下仅纯ZnO费米能级附近有载流子分布,这表明:压敏电阻界面有陷阱态,氧化锌压敏电阻界面电输运特性需用载流子陷阱对双肖特基势垒进行补充。     

籽晶分步包膜法掺杂改进ZnO的压敏电阻特性

通过籽晶分步包膜法ZnO复合掺杂物制备技术的研究,以及与其他三种不同工艺方法处理ZnO压敏电阻片掺杂物复合粉体的对比,特别是在复合掺杂物性能、混合浆料性能、喷雾造粒性能、电气性能和显微结构等方面的对比,得出籽晶分步包膜沉淀可以获得离子级混合均匀的ZnO复合掺杂物,经过喷雾造粒提高成型性能.最终,使ZnO压敏电阻片电位梯度和能量吸收能力得到了显著提高,分别达到2.6kV/cm和270J/cm3.     

籽晶分步包膜法掺杂改进ZnO的压敏电阻特性

通过籽晶分步包膜法ZnO复合掺杂物制备技术的研究,以及与其他三种不同工艺方法处理ZnO压敏电阻片掺杂物复合粉体的对比,特别是在复合掺杂物性能、混合浆料性能、喷雾造粒性能、电气性能和显微结构等方面的对比,得出籽晶分步包膜沉淀可以获得离子级混合均匀的ZnO复合掺杂物,经过喷雾造粒提高成型性能.最终,使ZnO压敏电阻片电位梯度和能量吸收能力得到了显著提高,分别达到2.6kV/cm和270J/cm3.     

Zn2SiO4掺杂对氧化锌压敏电阻性能的影响

采用普通陶瓷工艺制备了Zn2SiO4掺杂的氧化锌压敏电阻,研究了Zn2SiO4掺杂量对氧化锌压敏电阻的致密度,晶粒微观结构,小电流性能和通流能力的影响.结果表明:当Zn2SiO4掺杂量达到0.75％(摩尔分数)时,氧化锌压敏电阻晶粒致密均匀;电学性能得到改善,压敏电压梯度和非线性系数分别高达438 V/mm和85,漏电...     

影响氧化锌压敏瓷喷雾造粒粉体性能的因素

采用喷雾造粒技术制备氧化锌压敏电阻用粉体，其料浆的组成、造粒机的使用条件等因素对颗粒性能均有直接影响。     

银掺杂量对ZnO压敏电阻电性能的影响

通过传统的固相反应法在920℃制备了银掺杂的ZnO压敏电阻样品,考察了银掺杂量对样品烧结特性和电性能的影响。结果表明,银掺杂不利于样品的致密,但对于ZnO压敏电阻的电性能有明显的影响。当银在ZnO基体中的质量分数由15%增加到25%时,样品的压敏电压由1900V/cm降到600V/cm,对应的非线性系数由15.4降到9.0。这为进一步控制ZnO压敏电阻的电性能提供了新的途径。     

BaBSi玻璃对ZnVSb基压敏电阻结构与性能的影响

通过传统工艺制备出Ba-B-Si玻璃相掺杂的Zn-V-Sb基压敏电阻材料,研究了其微观结构及性能。结果表明,Ba-B-Si玻璃相的掺杂能降低Zn-V-Sb基压敏电阻试样的烧结温度,玻璃相中B2O3的含量过多,会使ZnO压敏电阻材料的伏安(V-I)特性变差;而Ba2 含量的增加,使ZnO压敏电阻材料的非线性系数上升。     

ZnO压敏电阻器性能的改进

采用溶胶一凝胶(Sol-Gel)法制备了ZnO压敏电阻器的复合纳米添加剂.用该添加剂与ZnO、Sb2O3混合球磨后按传统工艺制备出氧化锌压敏电阻器,对其电性能进行了测试,并对其结果进行了分析.实验结果表明,用Sol-Gel法制备的复合纳米添加剂制成的元件具有粉体掺杂均匀,晶粒粒径小且分布均匀的特点,其电性能也较固相合成工艺有了很大提高.     

(Nb,Mg,Al)多元掺杂对ZnO压敏材料电学性质的影响

研究了(Nb,Mg,Al)多元掺杂对ZnO压敏材料电学性能的影响。施主Nb离子的掺杂显著提高了压敏电阻的势垒高度,这与它能提供晶界势垒形成所必需的正电荷和负电荷直接相关。小半径离子Mg和Al易于处在ZnO的填隙位置,适量的掺杂也能提高晶界势垒高度,这与处在填隙位置的金属离子能提供正电荷和负电荷有关。而且填隙掺杂还能有效地改善陶瓷的致密度和均匀度,从而降低了ZnO压敏电阻漏电流、残压比和提高了非线性。(Nb,Mg,Al) 多元掺杂的ZnO压敏电阻的漏电流、残压比和非线性系数分别达到了 0.3 mA、V40kA/V1mA 2.5和a 110。     

TiO2掺杂对低压ZnO压敏电阻性能的影响

研究了TiO2掺杂量及制备工艺对ZnO压敏电阻性能的影响。TiO2掺压超过一定量时,压敏场强就不再降低,而非线性系数却一直下降,漏流迅速增大,使性能劣化。因此,要控制TiO2掺杂量在适当范围内。粉料煅烧温度和烧成的高低也直接影响ZnO压敏电阻性能。     

Controlling of electrical and interface state density properties of ZnO:Co/p-silicon diode structures by compositional fraction of cobalt dopant

The heterojunction diodes based on cobalt doped zinc oxide (ZnO) were prepared by sol-gel deposition method. The compositional fraction of cobalt dopant was varied to control the electrical parameters of the diode. Atomic force microscopy was used to determine the structural properties of ZnO:Co films. The ZnO:Co films have a microfiber structure and the structure of microfibers was changed with the cobalt dopant. The ideality factor values of 5% and 15% Co doped ZnO:Co/p-Si diodes were determined to be 3.49 and 7.51, respectively. The barrier height of the ZnO:Co/p-Si diodes were found to vary from 0.75 eV to 0.78 eV.It is concluded that the electrical and interface state density properties of ZnO:Co/p-Si diodes can be controlled by compositional fraction of cobalt dopant.     

Synthesis and photoluminescence characterizations of the Er3+-doped ZnO nanosheets with irregular porous microstructure

Er-doped ZnO nanosheets with high quality were synthesized by the hydrothermal and post-annealing techniques, and the effect of erbium dopant on the structures, morphologies and photoluminescence properties of the as-synthesized samples were determined using XRD, SEM, TEM, EDS, PL and Raman spectroscopy. The results showed that Er³⁺ ions were successfully incorporated into the crystal lattice of ZnO host, and some irregular porous microstructure with diameter of 3–10 nm could be seen on ZnO nanosheets as various doping concentrations. It was found that the crystallization and photoluminescence properties of ZnO nanosheets were strongly influenced by erbium doping concentration. The ultraviolet emission and deep level emission were both appeared in PL spectra, and the intensity of the whole deep level emission was enhanced with erbium doping, indicating the deep-level-defect luminescent centers were increased in the doped samples. Moreover, the crystallization of the samples became worse due to more defects by erbium doping.     

ZnO陶瓷材料的负阻特性

介绍了ＺｎＯ陶瓷的负阻特性，主要研究了ＭｎＯ２掺杂和Ｎｉ２Ｏ３掺杂对ＺｎＯ陶瓷负阻特性的影响。     

本征和Al3+掺杂ZnO薄膜的特性研究

采用溶胶-凝胶方法在载玻片衬底上制备了本征及不同Al3+掺杂浓度的ZnO:Al薄膜,利用X射线衍射(XRD)、原子力显微镜,紫外-可见光吸收光谱及霍尔效应研究了Al3+掺杂浓度对ZnO:Al薄膜结构和光电性能的影响。结果显示,ZnO:Al薄膜为六角纤锌矿晶体结构,具有很高的沿c轴的(002)择优取向,Al3+掺杂并没有改变ZnO的晶体结构,只是Al取代了Zn;掺杂前后薄膜样品均在ZnO带边吸收的位置有较强的吸收而在可见光范围吸收较小;并且当Al3+掺杂浓度为1.5%(摩尔百分比)时所获得的ZnO:Al薄膜具有最小的电阻率,为26Ωcm。     

ZnO微球的自组装及其发光性能研究

采用水热法合成了不同形貌的ZnO微球,利用XRD、TG-DSC、FT-IR、PL和SEM等分析了水热产物及其焙烧产物的形貌、结构和光致发光性能.结果表明,水热温度及焙烧过程对产物有显著影响,随着水热温度的升高,水热产物的形貌逐步由牡丹花状向鹅卵石状转变,经600℃焙烧1h后得到形貌各异、直径10～20 μm的ZnO微球,其中水热温度较低的ZnO微球为细纳米片组成的海胆状,水热温度较高的为ZnO纳米棒组装成的鹅卵石状.PL分析表明不同形貌的ZnO微球均具有绿光发射特性.     

The effects of Al doping and post-annealing via intrinsic defects on photoluminescence properties of ZnO:Eu nanosheets

Europium (Eu) and Aluminum (Al) co-doped ZnO nanosheets were synthesized by a hydrothermal method. The effects of Al concentration as a dopant and post-annealing of ZnO:Eu nanosheets on its structural, electrical and optical properties were investigated in detail. Prepared samples were characterized structurally using X-ray diffraction (XRD), morphologically using scanning electron microscopy (SEM) and optically using photoluminescence (PL) spectroscopy analyses. No diffraction peak related to dopants in XRD spectrum along with shift in peaks angles relevant to ZnO proved that Al and Eu ions were doped successfully into ZnO nanosheets. This study recommends that extrinsic doping and intrinsic defects have impressive roles on transferring energy to Eu ions at indirect excitations. Based on photoluminescence observations, intra-4f transitions of Eu³⁺ ions at an excitation wavelength of 390 nm allow a sharp red luminescence. Also the results showed that optical properties of ZnO can be tuned by varying the amount of Al concentration. In comparison with annealed Al doped ZnO:Eu nanostructures, as-grown samples showed the stronger PL peaks which indicated the effective role of intrinsic defects beside of extrinsic doping on energy transfer from ZnO host to Eu³⁺ ions which consequently led to producing the strong red emission from these sites.     

TiO_2掺杂对低压ZnO压敏电阻性能的影响

研究了 Ti O2 掺杂量及制备工艺对 Zn O压敏电阻性能的影响。Ti O2 掺杂超过一定量时 ,压敏场强就不再降低 ,而非线性系数却一直下降 ,漏流迅速增大 ,使性能劣化。因此 ,要控制 Ti O2 掺杂量在适当范围内。粉料煅烧温度和烧成温度的高低也直接影响 Zn O压敏电阻性能。     

Nb掺杂ZnO压敏电阻器的缺陷模型

对ＺｎＯ压敏电阻器高价Ｎｂ掺杂的缺陷模型进行了分析，据此模型对ＺｎＯ压敏电阻器的性质进行了讨论。     

棒状氧化锌的“绿色”水热合成及其气敏性能

以ZnCl2为原料,P123为形貌控制剂,采用水热合成技术制备了棒状氧化锌。通过XRD、SEM和TEM对其物相和形貌进行了分析,并测试了气敏性质。结果表明:重复利用滤液,得到的氧化锌形貌一致,直径约300nm,长度约10μm,且在170℃左右对体积分数为0.001%的乙醇、氨气、丙酮和氢气等还原型气体均有很好的响应,灵敏度也相当。