（英）磁控溅射制备纳米晶GZO/CdS双层膜及GZO/CdS/p-Si异质结光伏器件的研究

本文中,采用磁控溅射制备Ga掺杂ZnO (GZO)/CdS双层膜在p型晶硅衬底上以形成GZO/CdS/p-Si异质结器件。纳米晶GZO/CdS双层膜的微结构、光学及电学特性,通过XRD、SEM、XPS、紫外-可见光分光光度计和霍尔效应测试系统表征。GZO/CdS/p-Si异质结J-V曲线显示良好的整流特性。在±3V时,整流比IF/IR(IF和IR分别表示正向和反向电流)已达到21。结果表明纳米晶GZO/CdS/p-Si异质结具有好的二极管特性,在反向偏压下获得高光电流密度。纳米晶GZO/CdS/p-Si异质结显示明显的光伏特性。由于CdS晶格常数在GZO和晶Si之间,它能作为一个介于GZO和晶Si之间的缓冲层,能有效地减少GZO和p-Si之间的界面态。因此,我们获得了GZO/CdS/p-Si异质结明显光伏特性。     

磁控溅射制备纳米晶GZO/CdS双层膜及GZO/CdS/p-Si异质结光伏器件的研究

采用磁控溅射制备Ga掺杂ZnO (GZO)/CdS双层膜在p型晶硅衬底上以形成GZO/CdS/p-Si异质结器件。纳米晶GZO/CdS双层膜的微结构、光学及电学特性,通过XRD、SEM、XPS、紫外-可见光分光光度计和霍尔效应测试系统表征。GZO/CdS/p-Si异质结J-V曲线显示良好的整流特性。在±3 V时,整流比IF/IR(IF和IR分别表示正向和反向电流)已达到21。结果表明纳米晶GZO/CdS/p-Si异质结具有好的二极管特性,在反向偏压下获得高光电流密度。纳米晶GZO/CdS/p-Si异质结显示明显的光伏特性。由于CdS晶格常数在GZO和晶Si之间,它能作为一个介于GZO和晶Si之间的缓冲层,能有效地减少GZO和p-Si之间的界面态。因此,我们获得了GZO/CdS/p-Si异质结明显光伏特性。     

CH3NH3PbI3/p-Si异质结的光电特性研究

利用一步溶液法在p型Si衬底上生长有机/无机杂化钙钛矿CH3NH3PbI3薄膜,构成CH3NH3PbI3/p-Si异质结。利用原子力显微镜(AFM)、扫描电子显微镜(SEM)对薄膜形貌和结构进行表征,通过无光照和有光照条件下的电流-电压(I-V)、电容-电压(C-V)测试对异质结的光电特性进行研究。I-V测试结果显示CH3NH3PbI3/p-Si异质结具有整流特性,正反偏压为±5V时,整流比大于70,并在此异质结上观察到了光电转换现象,开路电压为10mV,短路电流为0.16uA。C-V测试结果显示Ag/CH3NH3PbI3/p-Si异质结具有与MIS(金属-绝缘层-半导体)结构相似的C-V特性曲线,与理想MIS的C-V特性曲线相比,异质结的C-V曲线整体沿电压轴向正电压方向平移。C-V特性曲线的这种平移表明Ag/CH3NH3PbI3/p-Si异质结界面存在界面缺陷,CH3NH3PbI3层也可能存在固定电荷。这种界面缺陷是导致CH3NH3PbI3/p-Si异质结开路电压的大幅度降低的重要原因。此外,CH3NH3PbI3薄膜的C-V测试结果显示其具有介电非线性特性,其介电常数约为4.64。     

简易化学水浴法制备SnO2/p-Si异质结光电性能

SnO2薄膜沉积在晶硅衬底上通过一种简单化学水浴法以制备n-SnO2/p-Si异质结光电器件,该化学水浴法非常便宜和方便。采用XRD、XPS、紫外-可见光分光光度计和霍尔效应测试系统表征了SnO2薄膜的微结构、光学和电学性能,对SnO2/p-Si异质结的I-V曲线进行测试并分析,获得明显的光电转换特性。     

简易化学水浴法制备SnO_2/p-Si异质结光电性能（英文）

通过一种简易化学水浴法将SnO_2薄膜沉积在晶硅衬底上以制备n-SnO_2/p-Si异质结光电器件,这种自制的化学水浴装置非常便宜和方便.采用XRD、SEM、XPS、PL、紫外-可见光分光光度计和霍尔效应测试系统表征了SnO_2薄膜的微结构、光学和电学性能,对SnO_2/p-Si异质结的I-V曲线进行测试并分析,获得明显的光电转换特性.     

LP-MOCVD法制作n-ZnO/p-Si异质结及其电致发光研究

采用低压-金属有机化学气相沉积法(LP-MOCVD)在(100)p-Si衬底上制备未掺杂n型ZnO薄膜,并制作了相应的n-ZnO/p-Si异质结器件.通过X射线衍射(XRD)、光致发光(PL)光谱和霍尔测试分别研究了所制备薄膜的结构、光学和电学特性.得到具有较高质量的n型ZnO薄膜.在室温条件下,测得了该类异质结器件正向注入电流下可见光和近红外区域的电致发光(EL).     

磁控溅射AlN∶Mg/ZnO∶Al异质结二极管及其光电特性的研究

利用磁控溅射方法,在ITO玻璃基底上分别溅射镁掺杂的氮化铝(AlN∶Mg)薄膜、铝掺杂的氧化锌(ZnO∶Al或AZO)薄膜,成功制备AlN∶Mg/ZnO∶Al透明异质结二极管.实验结果表明:AlN∶Mg/ZnO∶Al异质结具有明显的Ⅰ-Ⅴ整流特性,正向开启电压1V左右,在氙灯光照下,二极管的反向电流在5V偏置时达到3m...     

ZnO/SiC/Si异质结的光电转换特性

我们利用直流溅射制备了一系列的n-ZnO/n-SiC/p-Si和n-ZnO/p-Si异质结,通过研究他们的结构、I-V曲线、光生伏特效应和光响应谱。并且研究了他们的光电转换特性。发现n-ZnO/n-SiC/p-Si异质结的光电转换效率大约是n-ZnO/p-Si异质结的四倍。n-ZnO/n-SiC/p-Si异质结的光响应曲线也比n-ZnO/p-Si异质结强,表明n-ZnO/p-Si异质结加入3C-SiC中间层后光响应明显增强。在表面光电流谱中n-ZnO/n-SiC/p-Si异质结观察到两个拐点,而n-ZnO/p-Si异质结只观察到一个。通过以上研究可以看出3C-SiC在n-ZnO/n-SiC/p-Si异质结的光电转换中起了很大的作用.     

p-CuAlO2/(n-, p-)Si异质结的制备与电学性质

采用化学溶液法在n型和p型Si衬底上成功制备了单相CuAlO2薄膜。薄膜的电导率-温度曲线显示,薄膜在200K-300K温度范围内呈热激活导电模式,激活能约为0.3eV。电流-电压特性测试显示,p-CuAlO2/n-Si异质结具有明显的整流特性,开启电压约为1.6V,在±3V处的整流率约为35,而p-CuAlO2/p-Si同型异质结表现出类似肖特基结的电学性质,由于p-CuAlO2导电性远低于p-Si衬底,正向电流受空间电荷限制。     

ZnO/p-Si异质结构的电学输运特性

采用等离子体浸没离子注入沉积方法,在p型Si衬底上制备了具有整流特性的、非故意掺杂的以及掺氮的ZnO/p-Si异质结.非故意掺杂的ZnO薄膜为n型(电子浓度为1019cm-3数量级),掺氮的ZnO薄膜为高阻(电阻率为105Ω·cm数量级).非故意掺杂的ZnO/p-Si异质结在正向偏压下,当偏压大于0.4V,电流遵循欧姆定律.然而对于掺氮的ZnO/p-Si样品,当偏压小于1.0V时,电流表现为欧姆特性,当偏压大于2.5V时,电流密度与电压的平方成正比的关系.分别用Anderson模型和空间电荷限制电流模型对非故意掺杂和掺氮的ZnO/p-Si异质结二极管的电流输运特性进行了解释.     

Characterization of AZO/p-Si heterojunction prepared by DC magnetron sputtering

Al-doped ZnO (AZO) film was deposited by direct-current (DC) magnetron sputtering on p-Si (1 0 0) wafer to fabricate Al-doped n-ZnO/p-Si heterojunctions. The microstructural, optical and electrical properties of the AZO film were characterized by XRD, SEM; UV–vis spectrophotometer; four-point probe and Hall effect measurement, respectively. Results show that the AZO film is of good quality. The electrical junction properties were investigated by I–V measurement, which reveals that the heterojunction shows rectifying behavior under a dark condition. The ideality factor and the saturation current of this diode are 20.1 and 1.19×10⁻⁴ A, respectively. The value of I_F/I_R (I_F and I_R stand for forward and reverse current, respectively) at 5 V is found to be as high as 19.7. It shows fairly good rectifying behavior, indicating formation of a diode between AZO and p-Si. High photocurrent is obtained under a reverse bias when the crystalline quality of AZO film is good enough to transmit light into p-Si.     

硫掺杂纳米金刚石薄膜的图形化生长

利用电子增强热丝化学气相沉积(EACVD)技术,以CH4/H2/H2S/Ar为工作气体,SiO2/Si为衬底,制备了硫掺杂金刚石薄膜。研究了利用光刻技术实现薄膜的图形化生长。结果表明:以SiO2作掩模的光刻技术能够使得硫掺杂金刚石薄膜在光滑SiO2/Si基片上很好地图形化生长。Hall效应检测表明硫掺杂金刚石薄膜为n型,给出了n型金刚石/p-Si异质结的反向I-V特性曲线。     

ZnO/p-Si异质结的I-V及C-V特性研究

通过磁控溅射Al掺杂的ZnO陶瓷靶,在p-Si片上沉积n型电导的ZnO薄膜而制备了ZnO/p-Si异质结,并通过测试其光照下的I-V、C-V特性对其光电特性以及载流子输运特性与导电机理进行了研究。研究表明ZnO/p-Si异质结存在良好的整流特性与光电响应,可以广泛应用在光电探测和太阳电池等领域。由于在ZnO/p-Si异质结界面处的导带补偿与价带补偿相差太大的缘故,在正向电压超过1V时,导电机理为空间电荷限制电流导电。同时,研究表明ZnO/p-Si异质结界面存在大量界面态,可以通过减小界面态进一步提高其光电特性。     

Electrical and optical properties of ZnO/Si heterojunctions as a function of the Mg dopant content

Undoped and Mg-doped ZnO thin films prepared by a sol–gel process were deposited on p-Si and glass substrates via spin coating. The electrical and optical properties of the films were investigated. Atomic force microscopy images revealed that the ZnO films are formed from fibers consisting of nanoparticles. The electrical conductivity mechanism of the films was investigated. The I–V characteristics of Al/ZnO/p-Si samples showed rectification behavior with a rectification ratio that depended on the applied voltage and the Mg doping ratio. ZnO/p-Si heterojunction diodes exhibited non-ideal behavior with an ideality factor greater than unity that could be ascribed to the interfacial layer, interface states, and series resistance. The barrier height for undoped and Mg-doped ZnO/p-Si diodes was in the range 0.78–0.84 eV. The results demonstrate that the electrical properties of ZnO/p-Si heterojunction diodes are controlled by the Mg dopant content and suggest that the optical bandgap of these ZnO films can be tuned using the Mg level.     

Temperature coefficients of grain boundary resistance variations in a ZnO/p-Si heterojunction

Heteroepitaxial undoped ZnO films were grown on Si (100)substrates by radio-frequency reactive sput tering,and then some of the samples were annealed at N<,2>-800 ℃(Sample 1,S1)and O<,2>-800℃(Sample 2,S2)for 1 h,respectively.The electrical transport characteristics of a ZnO/p-Si heterojunction were investigated.We found two interesting phenomena.First,the temperature coefficients of grain boundary resistances of S1 were positive(positive temperature coefficients,PTC)while that of both the as-grown sample and S2 were negative(negative temperature coefficients,NTC).Second,the Ⅰ-Ⅴ properties of S2 were similar to those common p-n junctions while that of both the as-grown sample and S1 had double Schottky barrier behaviors,which were in contradiction with the ideal p-n heterojunction model.Combined with the deep level transient spectra results,this revealed that the concentrations of intrinsic defects in ZnO grains and the densities of interfacial states in ZnO/p-Si heterojunction varied with the different annealing ambiences,which caused the grain boundary barriers in ZnO/p-Si heterojunction to vary.This resulted in adjustment electrical properties of ZnO/p-Si heterojunction that may be suitable in various applications.     

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.     

Photoelectric conversion characteristics of ZnO/SiC/Si heterojunctions

A series ofn-ZnO/n-SiC/p-Si and n-ZnO/p-Si heterojunctions were prepared by DC sputtering. Their struc-tural properties, Ⅰ-Ⅴ curves, photovoltaic effects and photo-response spectra were studied. The photoelectric conver-sion characteristics of n-ZnO/n-SiC/p-Si and n-ZnO/p-Si heterojunctions were investigated. It is found that the pho-toelectric conversion efficiency of the n-ZnO/n-SiC/p-Si heterojunction is about four times higher than that of the n-ZnO/p-Si heterojunction. The photovoltaic response spectrum indicated that the photoresponse curve of n-ZnO/n-SiC/p-Si increased more strongly than that of n-ZnO/p-Si with the wavelength increasing. It shows that the photore-sponse ofn-ZnO/p-Si can be enhanced when inserting a 3C-SiC layer between ZnO and Si. There is one inflexion in the photocurrent response curve of the n-ZnO/p-Si heterojunction and two inflexions in that of the n-ZnO/n-SiC/p-Si het-erojunction. It is clear that the 3C-SiC plays an important role in the photoelectric conversion of the n-ZnO/n-SiC/p-Si heterojunction.     

3C-SiC/Si异质结二极管的高温特性

研究了低压化学气相淀积方法制备的n-3C-SiC/p-Si(100)异质结二极管(HJD)在300～480K高温下的电流密度-电压(J-V)特性.室温下HJD的正反向整流比(通常定义为±1V外加偏压下)最高可达1.8×104,在480K时仍存在较小整流特性,整流比减小至3.1.在300K温度下反向击穿电压最高可达220V.电容-电压特性表明该SiC/Si异质结为突变结,内建电势Vbi为0.75V.采用了一个含多个参数的方程式对不同温度下异质结二极管的正向J-V实验曲线进行了很好的拟和与说明,并讨论了电流输运机制.该异质结构可用于制备高质量异质结器件,如宽带隙发射极SiC/Si HBT等.