Realization of Ultraviolet Electroluminescence from ZnO Homojunction Fabricated on Silicon Substrate with p-Type ZnO:N Layer Formed by Radical N2O Doping

ZnO homojunction light-emitting diodes are fabricated on Si（100） substrates by plasma assisted metal organic chemical vapour deposition. A p-type layer of nitrogen-doped ZnO film is formed using radical N2O as the acceptor precursor. The n-type ZnO layer is composed of un-doped ZnO film. The device exhibits desirable rectifying behaviour with a turn-on voltage of 3.3 V and a reverse breakdown voltage higher than 6 V. Distinct electrolumineseence emissions centred at 395nm and 490nm are detected from this device at forward current higher than 20mA at room temperature.     

Ag掺杂对ZnO薄膜的光电性能影响

采用超声喷雾热分解法在石英衬底上以醋酸锌水溶液为前驱体,以硝酸银水溶液为Ag掺杂源,以高纯O2为载气生长了Ag掺杂ZnO(ZnO∶Ag)薄膜。研究了Ag掺杂ZnO薄膜的表面结构、电学和光学性质。结果表明所得ZnO∶Ag薄膜表面结构良好,扫描电子显微镜(SEM)测试表明薄膜表面光滑平整,结构致密均匀;在室温光致发光(PL)光谱中检测到很强的近带边紫外发光峰;透射光谱中观测到非常陡峭的紫外吸收截止边和较高的可见光区透过率,表明薄膜具有较高的晶体质量与较好的光学特性;霍尔效应测试表明,在550℃下获得了p型导电的ZnO∶Ag薄膜。     

能量色散-X射线荧光光谱测定中草药痕量镉、铅、铜

为寻求一种能够直接对中草药中重金属进行快速检测的方法,采用压片法对样品进行前处理,建立了能量色散-X射线荧光光谱法快速检测中草药中痕量重金属镉、铅、铜元素的方法。在20 min即可完成检测,镉、铅、铜检出限分别为0.072、0.207、0.340 mg/kg,测试结果表明与原子吸收和ICP-MS相比,本方法数据稳定性和准确度良好,具有快速、准确、简单的优点,能够满足药典中对重金属元素的限量要求,适用于现场快速检测与质量控制检测。     

水热法制备Co掺杂ZnO纳米棒及其光学性能

采用水热法在石英衬底上以Zn(CH3COO)2.2H2O和Co(NO3)2.6H2O水溶液为源溶液,以C6H12N4(HMT)溶液作为催化剂,在较低温度下制备了Co掺杂的ZnO纳米棒。采用X射线衍射(XRD)和扫描电子显微镜(SEM)对所生长ZnO纳米棒的晶体结构和表面形貌进行了表征,考察了Co掺杂对ZnO纳米棒微观结构和对发光性能影响的机制。结果表明:Co掺杂的ZnO纳米棒呈六方纤锌矿结构,具有沿(002)面择优生长特性,Co掺杂使ZnO纳米棒的直径变细;同时室温光致发光(PL)谱检测显示Co掺杂ZnO纳米棒具有很强的近带边紫外发光峰,而与深能级相关的缺陷发光峰则很弱。本研究采用水热法在石英衬底上于较低温度下生长出了具有较高光学质量的Co掺杂ZnO纳米棒。     

Enhanced p-Type ZnO Films through Nitrogen and Argentum Codoping Grown by Ultrasonic Spray Pyrolysis

The N-Ag codoped ZnO films are deposited on quartz glass substrates by ultrasonic spray pyrolysis technology. The results indicate that the p-type conductivity in ZnO films is greatly enhanced by the double acceptor codoping of N and Ag compared with that of Ag- and N-monodoped ZnO films, and the NAg codoped low-resistivity p-type ZnO films with the resistivity of 1.05 Ω·cm, relatively high carrier concentration of 5.43×10^17 cm^-3, and Hall mobility of 10.09 cm^2 V^-1s^-1 are obtained under optimized conditions. This achievement confirms that p- type ZnO with acceptable properties for optoelectronic applications could be realized by simultaneous codoping with two potential acceptors.