基于W-SiO_2双金属陶瓷结构的高效率太阳能选择性吸收薄膜的优化和制备（英文）

理论优化并成功制备了一种以W-SiO_2双金属陶瓷作为吸收层的太阳能选择性吸收薄膜,同时提高了薄膜在太阳辐射波段的吸收并降低了在红外波段的热辐射。研究了包括金属反射层材料、吸收层金属体积分数等因素对薄膜整体吸收效率的影响。基于对Si和K9玻璃基底上生长的不同金属体积分数的W-SiO_2陶瓷薄膜光学常数的研究,利用磁控溅射方法制备出如下膜系:W(～150 nm)/W-SiO_2(94nm,0.67HVF)/W-SiO_2(34nm,0.27LVF)/SiO_2(47nm)。膜系实际测量结果与仿真结果完全吻合,在250～1 500 nm宽光谱波段实现了高达95.3%的吸收率,并且在600 K温度下达到0.124的低热辐射率。该四层膜系结构简单,易于制备,有很强的实际应用前景。     

用热蒸发法制备的Cu2ZnSnS4 薄膜的光电性能

在室温下用真空热蒸发法在玻璃基片上制备Sn/Cu/ZnS 前躯体膜层,然后对其在550C 下在硫气氛中硫化3小时以制得Cu₂ZnSnS₄ (CZTS) 多晶薄膜。对该薄膜进行X射线衍射（XRD）、能量色散X射线光谱（EDX）、紫外可见近红外分光光度计、霍尔测量系统和3D光学显微镜等分析测试。实验结果表明,当[Cu]/([Zn] [Sn]) =0.83和[Zn]/[Sn] =1.15时,该CZTS薄膜在光子能量范围在1.5 - 3.5 eV 时其吸收系数大于4.010₄cm_-1 ,直接带隙为1.47 eV。其载流子浓度、电阻率和迁移率分别为7.9710₁₆ cm_-3, 6.06 Ω.cm, 12.9 cm₂/(V.s), 导电类型为p型。因此,所制备出的CZTS 薄膜适合作为太阳电池的吸收层材料。     

溅射压强对ITO/Cu2O复合膜结构和光学性能的影响

利用脉冲磁控溅射制备技术,以氧化铟锡(ITO)导电玻璃为基底,采用单质金属Cu 靶作为溅射靶,在O₂和Ar的混合气氛下沉积了Cu₂O薄膜。通过调控溅射压强,研 究了脉冲磁控溅射沉积法在不同溅 射压强下对Cu₂O薄膜的物相结构、表面形貌及光学性能的影响。结果表明,在O₂、Ar流 量比(O₂/Ar)为20∶90的气 氛条件下,在2～3Pa的溅射压强范围内,可获得纯相的Cu₂O薄膜;薄膜表面形貌依赖于 溅射压强,薄膜表面粗糙度的 均方根(RMS)值随溅射压强的增大而减小;在ITO上沉积Cu₂O 薄膜后,薄膜的光学吸收边红移至780 nm, ITO/Cu₂O复合膜的光谱吸收范围拓展至300～780 nm,复合膜的吸收强度随溅射压强的增 大而减小,光学带隙E_g 随溅射压强的增大而增大,E_g值为2.28～2.39eV。     

退火Cu2O薄膜的结构及光学特性

采用射频(RF)磁控溅射单质金属铜(Cu)靶, 在O₂和Ar的混合气氛下制备了Cu₂O薄 膜,并在N₂气氛下对预沉积的Cu₂O薄膜进行快速光热退火(RTA)处理,研究了 衬底温度及退火温度对Cu₂O 薄膜的生长行为、物相结构、表面形貌及光学性能的影响。结果表明,衬底温度在300℃以 下预沉积的Cu₂O薄膜 为非晶薄膜,退火处理对Cu₂O薄膜的结晶行为有明显影响,在N₂气氛下对Cu₂O薄膜进 行退火处理不影响薄膜的物 相结构;预沉积和退火Cu₂O薄膜在650nm以下波长范围内均有较强 吸收,吸收强度随退火温度的增加而增强,薄 膜在400nm以下波长范围内出现两个由缺陷引起的中间带(IB)吸收行 为,快速热退火处理不能减少或消除薄膜沉积 过程中形成的缺陷态;退火处理影响薄膜的光学带隙Eg,预沉 积薄膜经600℃退火处理,E_g值增大了 0.26eV。     

SiO2钝化膜对非极性AlGaN-MSM紫外探测器的影响

采用SiO₂钝化膜方法对引入低温AlN插入层的高 温MOCVD外延生长的未掺杂的非极性AlGaN外 延薄膜制备了金属-半导体-金属(MSM)结构的紫外光电探测器。研究了磁控溅射SiO₂钝 化膜对探测器光电性能的提 升。暗电流测试表明,钝化处理使探测器的暗电流可以降低了2-3个数量级。在5V偏压下 , 通过光谱响应测试发现,经过钝化处理的探测器在300 nm处具有陡峭 的截止边,具有很好 的深紫外特性,光谱响应范围提高了3个数量级,抑制比高达10⁵。     

MoO3修饰氧化石墨烯作为空穴注入层影响研究

研究了MoO₃修饰氧化石墨烯(GO)作为空穴注入层的影响。采用旋涂的方法制备了GO, 再真空蒸镀修饰层MoO₃,得到了空穴注入能力强和透过率高的复合薄膜。MoO₃的厚分 别采用0、3、5和8nm。通过优化MoO₃的厚度发现,当MoO₃的厚为5nm时,复合薄膜 的透过率达到最大值,在 550nm的光波长下透光率为88%,且此时采用 复合薄膜作为空穴注入层制备的结构为 ITO/GO/MoO₃(5nm)/NPB(40nm)/Alq₃(40nm)/LiF(1nm)/Al(100nm)的有机电致发光器件(OLED)性能 最佳。通过对OLED进一步的优化,改变Alq₃的厚度,分别取50、60和70nm,测量其电压 、电流、亮度、色坐标和电致发光(EL)光谱等参数发现,当Alq₃的厚为50nm时器件性能最 佳。最终制备了结构为ITO/GO/MoO₃(5nm)/NPB(50nm)/Alq₃(50nm)/LiF(1nm)/Al(100 nm)的OLED,在电压为10V时,最大电流效率达到5.87cd/A,与GO单独作为空穴注入层制备的器件相比,提高了50%。     

空芯带隙型光子晶体光纤残余双折射特性研究

采用磁控溅射法, 在玻璃基底上一步沉积In₂S₃薄膜。研究了溅射功率对In₂S₃薄膜的成分、结构、表面形貌和光电性能的影响。结果表明: 所制备的所有薄膜均为β-In₂S₃, 无杂相存在, 且具有(222)面择优生长特性。溅射功率对薄膜的成分、厚度和结晶度具有明显的影响, 并因此影响薄膜的光学和电学性能。薄膜在100W沉积时最接近化学计量比, 薄膜的透过率随着溅射功率增大在500nm波段附近显著提高, 禁带宽度达到2.45eV, 同时电流密度增大两个数量级。     

InyAl1-yAs线性渐变缓冲层对InP基HEMT材料性能的影响

采用气体源分子束外延（GSMBE）技术,研究了InP衬底上In_yAl_1-yAs线性渐变缓冲层对In_0.66Ga_0.34As/In_yAl_1-yAs高迁移率晶体管（HEMT）材料特性影响。研究了不同厚度和不同铟含量的In_yAl_1-yAs线性渐变缓冲层对材料的表面质量、电子迁移率和二维电子气浓度的影响。结果表明,在300 K（77 K）时,电子迁移率和电子浓度分别为8 570 cm²/（Vs）^-1（23 200 cm²/（Vs）-1）3.255E12 cm^-2（2.732E12 cm^-2）。当In_yAl_1-yAs线性渐变缓冲层厚度为50 nm时,材料的表面形貌得到了很好的改善,均方根粗糙度（RMS）为0.154 nm。本研究可以为HEMT器件性能的提高提供强有力的支持。     

SiNx/SiOxNy叠层结构防潮能力的研究

研究了等离子体增强化学气相沉积(PECVD)工艺参数对SiN_x及SiO_xN_y防潮能力的影响,并测试了SiN_x/SiO_xN_y叠层薄膜的水汽渗透速率(WVTR)。实验结果表明:单层SiN_x薄膜和SiO_xN_y薄膜都存在临界厚度,当膜厚大于临界值时,继续增大厚度不会明显改善薄膜的WVTR。当沉积温度从50℃提高到250℃,SiN_x薄膜的WVTR从0.031g/(m²·day)降至0.010g/(m²·day)。SiO_xN_y沉积时,增大N₂O通入量对薄膜的WVTR影响不明显,但可以有效改善薄膜的弯曲性能。最后,4个SiN_x/SiO_xN_y叠层膜的WVTR下降到了4.4×10-4g/(m²·day)。叠层膜防潮能力的显著提升归因于叠层结构可以有效解耦层与层之间的缺陷,延长水汽渗透路径。     

MgF2/Se薄膜封装层对OLED性能及寿命的影响

有机电致发光器件(OLEDs)在使用过程中,易受到 空气中水汽、氧气及其它污染物的影响从而导致其工作寿命降低。本文将具有良好光透过率 和热稳定性的MgF₂薄膜与在水汽和氧气中具有良好稳定性的Se薄膜通过真空蒸镀制成复 合薄膜作为OLEDs的封装层,以达到提高器件使用寿命的目的。器件各功能层蒸镀完成后, 保持真空度(3×10－4 Pa)不变,在阴极表面蒸镀MgF₂/Se薄 膜封装层。比较 了绿光OLED器件(器件结构为ITO/CuPc/NPB/Alq₃:C-545T/Alq ₃/LiF/Al)封装前后的亮度-电压-电流密度特性、电致发光光谱及寿命。研究 发现,经过MgF₂/Se封装后,器件的电流密度-电压特性、亮度和发光光谱几乎没 有受到影响,二者的光谱峰都在528 nm处,色坐标(CIE)分别为(0.3555,0.6131)和(0.3560,0.6104),只是起亮电压由3V变为4V;器件的寿命由原来的175h变为300h,提高了1.7倍 。因此,MgF₂/Se薄膜是一种有效的OLEDs无机薄膜封装层。     

Research opportunities in polycrystalline compound solar cells

Polycrystalline photovoltaic (PV) materials show substantial promise for achieving the U.S. Department of Energy PV costs and performance goals. Cadmium telluride (CdTe) and CuInSe₂ (CIS) both have recently demonstrated device efficiencies in the 15 percent range with promise of achieving 20 percent efficiencies. Large area thin film CIS and CdTe modules in the 0.4 to 0.7 m² size have also been fabricated with aperture efficiencies approaching ten percent. In spite of these results, polycrystalline thin film materials are relatively unexplored. Fundamental research opportunities in materials for thin film solar cells can be categorized under three major headings, from the most general to the most specific: areas with long-range potentialities, areas with a larger exploratory content, and areas with specific need. Each of these issues can play a vital role in the development of improved solar cells. The discussion of research opportunities in this paper starts with the more general opportunities and works its way to the most specific ones: (i) updating the basic investigation of defect properties and compensation in Group II-VI and related materials; exploring the basic materials science of the growth process for synthesis from layers of the elements, and exploring the potentials of bandgap engineering; (ii) search for new materials, interactions between defects and grain boundaries in polycrystalline materials, and exploration of the p-i-n structure for solar cells in a more general way; and (iii) doping of and contacts to p-CdTe, junction transport and effects of heat treatments on CdTe and CuInSe₂, and development of Group II-VI ternaries.     

Phase relations in the system ln-CulnS2

By DTA and x-ray diffraction the phase relations in the pseudobinary system In-CuInS₂ have been investigated. CuInS₂ hs a melting point of 1090° C and within this system there is a broad region of liquid immiscibility. A four phase invariant reaction exists at 633° C which is of the form: L₂ = L₁+ CuInS₂ + InS.     

Enhanced photovoltaic performance in TiO2/P3HT hybrid solar cell by interface modification

A TiO2/P3HT hybrid solar cell was fabricated by infiltrating P3HT into the pores of TiO2 nanorod arrays. To further enhance the photovoltaic performance, anthracene-9-carboxylic acid was employed to modify the interface of TiO2/P3 HT before P3HT was coated. Results revealed that the interface treatment significantly enhances the photovoltaic performance of the cell. The efficiency of the hybrid solar cells reaches 0.28% after interface modification, which is three times higher compared with the un-modified one. We find that except for the increased exciton dissociation efficiency recognized by the previous reports, the suppressing of electron back recombination is another important factor leading to the enhanced photovoltaic performance.     

Metal-silicon reaction rates—the effects of capping

Evidence is presented showing that the presence of the commonly used anti-reflection coating material Ta₂O₅ on the free surface of contact metallization can either suppress or enhance, depending on the system, the interaction that takes place at elevated temperatures between the metallization and the underlying Si. The cap layer is shown to suppress both the generation and annihilation of vacancies at the free surface of the metal which are necessary to support metal-Si interactions. Evidence is also presented indicating that the mechanical condition of the free metal surface has a significant effect on the metal-silicon reaction rate.     

电化学沉积铜铟镓硒薄膜中溶液温度的影响

摘要：使用电化学沉积技术可低成本制备铜铟镓硒（CIGS）薄膜,并应用于太阳电池。本文研究恒压法电化学沉积中电解液温度对制备CIGS薄膜性能的影响。以柠檬酸钠为缓冲剂,Mo玻璃为衬底,电位恒定为-0.75V,电解液温度分别为20,40,60℃,均得到厚度约为1μm的CIGS薄膜。结果表明以电沉积法成功制备出黄铜矿结构的CIGS多晶薄膜,晶粒均匀,X射线衍射谱表明其组分为CuIn0.7Ga0.3Se2。电解液温度对制备薄膜的质量有显著影响,随着电解液温度升高,CIGS薄膜的结晶性变好,晶粒尺寸呈现增大趋势。电解液温度变化对薄膜组分无明显影响。     

Nanostructure effect of V2O5 buffer layer on performance of polymer-fullerene devices

Nanostructure of solar cell materials is often essential for the device performance. V₂O₅ nanobelt structure is synthesized with a solution process and further used as an anode buffer layer in polymer solar cells, resulting insignificantly improved power conversion efficiency (PCE of 2.71%) much higher than that of devices without the buffer layer (PCE of 0.14%) or with V₂O₅ powder as the buffer layer (1.08%). X-ray diffraction (XRD) results indicate that the V₂O₅ nanobelt structure has better phase separation while providing higher surface area for the P3HT:PCBM active layer to enhance photocurrent. The measured impedance spectrums show that the V₂O₅ nanobelt structure has faster charge transport than the powder material. This work clearly demonstrates that V₂O₅ nanobelt has great potential as a substitute of the conventionally used PEDOT-PSS buffer layer for high performance devices.     

Zn1?xMgxO用于 CIGS 太阳电池的研究进展

Zn1-xMgxO透过率高、带隙可调,且与CIGS太阳电池在晶格和能带结构上匹配良好,可用作CIGS太阳电池缓冲层、窗口层,因此制备高质量的Zn1-xMgxO薄膜是提高太阳电池性能的关键。文章介绍了Zn1-xMgxO薄膜的结构特性、光学特性及制备方法;从Mg含量、Zn1-xMgxO膜厚及Zn1-xMgxO/CIGS界面处缺陷密度等方面概述了Zn1-xMgxO用于CIGS太阳电池的研究进展,并比较了Zn1-xMgxO与In2S3,ZnS,CdS等其他材料作缓冲层的CIGS太阳电池性能的差别。     

Impact of Cu-rich growth on the Cu2ZnSnSe4 surface morphology and related solar cells behavior

In order to study the influence of Cu-rich growth on the performance of the Cu₂ZnSnSe₄ (CZTSe) thin film solar cells, a multi-stage co-evaporation process is applied. The CZTSe films are grown at a lower substrate temperature to reduce the existence time of Cu_xSe_y at the first period caused by the volatility of SnSe_x. This study examines the surface morphology and device performance in Cu-rich growth and close-to-stoichiometric growth. Although the grain size of Cu-rich growth film increases a little, the difference was not dramatic as the results of CIGS reported previously. A model based on the grain boundary migration theory is proposed to explain the experimental results. The mechanisms of Cu-rich growth between CZTSe and CIGS might be different.     

介稳态TiCl4醇水溶液水解制备TiO2致密层及其在无机-有机杂化异质结钙钛矿太阳电池中的应用

致密层作为钙钛矿太阳电池的重要组成部分, 对其制备方法, 工艺及微结构等性质的研究对提高钙钛矿太阳电池的光伏性能具有重要影响. 本文利用介稳态的TiCl₄醇水溶液作为前驱体溶液, 通过旋涂水解制备TiO₂致密层, 并研究了前驱体溶液不同醇水比对致密层微结构及其相应太阳电池光伏性能的影响. 结果表明, 将2 mol.L_-1的TiCl₄的水溶液按醇水体积比3:1的比例用异丙醇稀释后所制备的TiO₂致密层其厚度为126 nm, 且相应的太阳电池取得最高的光电转换效率10.6 %.