磁控溅射Sn/Cu/ZnS预置层后硫化法制备Cu_2ZnSnS_4薄膜及其性能研究

采用磁控溅射法制备Sn/Cu/ZnS金属预置层,结合硫化热处理制备Cu_2ZnSnS_4薄膜。利用X射线衍射仪(XRD)、拉曼光谱仪(Raman)、扫描电子显微镜(SEM)、紫外-可见分光光度计(UV-VIS)和霍尔测试系统等一系列测试方法对样品结构、各组分含量、表面形貌、光学带隙及电学性能进行表征及计算。研究结果表明Sn/Cu/ZnS金属预置层经490和540℃硫化热处理后的薄膜均为单一Cu_2ZnSnS_4相,其中,540℃硫化热处理后的薄膜结晶度较高,且薄膜表面平整致密,禁带宽度约为1.58 eV,呈现P型导电。     

透明导电ZnO:Al(ZAO)薄膜的结构及光电特性研究

ZAO薄膜是一种n型氧化物半导体材料,由于其大的载流子浓度和光学禁带宽度而表现出优良的光电特性。本实验采用射频磁控溅射工艺在无机玻璃衬底上制备ZAO薄膜,靶材为ZAO(3wt%Al2O3)陶瓷靶。系统研究了各工艺参数,如工作气压、射频功率、衬底温度和热处理条件对其结构和光电特性的影响。X射线衍射谱表明ZAO薄膜的(002)衍射峰的位置与纯ZnO晶体相比向低角度方向移动,薄膜中各晶粒具有六角纤锌矿晶体结构且呈c轴择优取向。原位制备的ZAO薄膜经热处理后电阻率降至7 5×10-4Ω·cm,可见光透过率在85%以上。     

Cu（In,Al）Se2薄膜太阳电池

Cu(In,Al)Se2(CIAS)化合物薄膜太阳电池属于Ⅰ-Ⅲ-Ⅵ2族化合物薄膜太阳电池,由同族的Al来替代CuInSe2(CIS)中的In,及Cu(In,Ga)Se2(CIGS)中的Ga和In。具有黄铜矿结构的Ⅰ-Ⅲ-Ⅵ2族化合物半导体材料可作为吸收层用于光伏电池。用渗入CIS中得到具有黄铜矿结构的CIGS,并且可根据Ga/(In+Ga)调节禁带宽度提高转化效率,但Ga的掺入调节禁带宽有限。以Al替代Ga,不仅可大幅降低成本,同时由于形成CuAlSe2相的能隙为2.7eV,因此调节Al/(In+Al)的比例可更宽泛地调节Cu(In,Al)Se2(CIAS)能禁带宽度。目前CIAS制备工艺以真空镀膜方法为主,包括真空蒸镀、磁控溅射、脉冲激光等。在非真空方法中,研究者们尝试了电沉积的方法成功制得单相的CIAS吸收层薄膜,而用如丝网印刷等低成本工艺CIAS薄膜尝试还少见报导。本文详细介绍了CIAS制备方法及工艺,并提出CIAS研究的一些建议。     

Fe膜硫化合成FeS2薄膜的光电性能

研究了纯Fe在200－600℃硫化10h 及500℃硫化1－10h条件下形成FeS2薄膜过程中的结构，光吸收，禁带宽度及电阻率的变化规律，纯Fe膜虽在200℃即有硫化反应发生，但只有在300℃以上硫化时，薄膜才会出现明显的禁带宽度，并随硫化温度升高，禁带宽度下降，硫化时间对薄膜禁带宽度影响不明显，随硫化温度升高及硫化时间延长，薄膜电阻率上升，由于硫化参数的变化能够引起薄膜结构，晶体缺陷及薄膜完整的性的变化，因此可以导致薄膜光电性能的变化。     

铜锌锡硫系薄膜太阳电池的专利分析

铜锌锡硫(CZTS)系薄膜太阳电池因其高吸收系数、适宜的带隙宽度而成为太阳电池领域非常有前途的光吸收层材料。本文针对CZTS系薄膜太阳电池进行专利技术综述的分析,对国内外专利申请情况进行梳理,为国内薄膜太阳电池研究发展提供参考。     

厚度对FeS2薄膜的光电性能的影响

采用Fe膜硫化工艺制备不同厚度的FeS2薄膜。研究了不同厚度FeS2薄膜的晶体结构，电阻率，载流子浓度，光吸收系数以及禁带宽度（Eg)。结果表明，随着薄膜厚度的增加，FeS2的电阻率升高，载流子浓度下降，在高吸收区FeS2薄膜的光吸收系数也呈下降趋势。当薄膜厚度小于130nm时，薄膜厚度增加可导致其禁带宽度上升，当薄膜厚度大于130nm时，薄膜厚度增大反而会导致禁带宽度下降。     

用MOCVD方法制备ZnO：B透明导电薄膜及其性能优化

采用金属氧化物化学气相沉积(MOCVD)方法在石英衬底上生长氧化锌(ZnO)薄膜.改变薄膜材料的生长温度和掺杂气体硼烷(B2H6)的流速,制备一系列薄膜样品.通过x-射线衍射(XRD)、扫描电子显微镜(SEM)、透过率、反射率、电阻率和原子力显微镜(AFM)等测试分析,研究了材料生长温度和B2H6流速对薄膜生长速度、微观结构、薄膜晶向、光学透过率、光学禁带宽度、电阻率、表面粗糙度等特征参量的影响,经过优化实验条件,获得薄膜电阻率在10-3Ω·cm量级,可见光区域光学透过率在85%以上,成功制备低电阻率高光学透过率的ZnO透明导电薄膜.     

直流磁控溅射法制备单一相高质量β-FeSi2薄膜

报道了在单晶Si(100)衬底上,采用室温直流磁控溅射Fe-si组合靶的方法,并经过后续气氛退火来制备β-FeSi2薄膜的结果.主要研究了退火时间、退火温度等实验条件对样品结构特性、光学特性和电学特性的影响,制备出了单一相高质量的βFeSi2薄膜.霍尔测试表明未掺杂薄膜是P型导电的,载流子浓度5.7147×1016 cm-3,空穴迁移率168cm2/Vs.由反射一透射法得到薄膜的禁带宽度为0.879eV,吸收系数在光子能量为1.0eV时达到了1.42×105cm-1.基于以上优异的光电性能,β-FeSi2薄膜可望用作太阳电池的有源层.     

KCl浓度对电沉积ZnO量子点敏化太阳能电池光电性能的影响

文章采用恒电位沉积法在导电玻璃上制备了ZnO薄膜,研究了沉积液中KCl浓度对ZnO薄膜结构的影响,将制备的ZnO薄膜应用于量子点敏化太阳能电池(QDSCs)的光阳极,而后分析了该太阳能电池的光电转换效率。文章还利用X射线衍射(XRD),以及扫描电子显微镜(SEM),表征ZnO薄膜的结构和形貌,以紫外-可见吸收光谱(UV-Vis)表征量子点敏化前后光阳极的光吸收特性,利用电化学工作站测试不同形貌ZnO-CdS太阳能电池的光电转换特性。分析结果表明:当KCl浓度为0.075 mol/L时,ZnO薄膜呈现出均匀多孔的纳米片结构,以该ZnO薄膜为光阳极的QDSC的开路电压为0.35 V,短路电流密度为3.17 mA/cm~2,光电转换效率为0.36%;与未添加KCl的ZnO薄膜相比,多孔片状ZnO薄膜的活性位点能够与电解液充分接触,这样提高了光阳极内光生电子的注入效率,从而使太阳能电池具有更高的的光电转换效率。     

衬底温度对PLD法沉积CdS及ZnS薄膜材料的影响

以ITO玻璃为衬底,利用脉冲激光沉积(PLD)法在温度为50、200和400℃下制备了CdS、ZnS薄膜。测量分析了温度对CdS及ZnS薄膜的透射光谱特性、光学带隙、Raman光谱特性等的影响。结果显示,在实验温度范围内:①ZnS薄膜比CdS薄膜透射性能好,光学带隙大;②ZnS薄膜的Raman光谱复杂,Raman特征峰较弱;CdS薄膜的Raman特征峰明显;③随温度升高,CdS与ZnS相比禁带宽度增加明显、Raman特征峰增高变窄。对此现象进行了解释,为利用CdS或ZnS薄膜作为CIGS薄膜太阳电池缓冲层提供了参考。     

电共沉积InGaAs薄膜材料

阐述了电共沉积方法制备发射光波长近于1.3-1.5um的InGaAs薄膜材料,用能谱分析仪进行薄膜成分分析,用分光光度计和单色仪测量薄膜的透射率,同时测量了薄膜I－V特性,导电类型,厚度及其表面形貌,分析结果表明该方法是半导体薄膜材料制备的一种新途径。     

AlN薄膜对太阳能吸收率的研究

采用磁控溅射方法,在高纯氩气和氮气混合气氛下成功制备出Al(W)-AlN系太阳能选择性吸收薄膜。借助吸收光谱分析,比较了Al、W两种反射层材料上制备单层AlN和多层AlN薄膜的光谱吸收特性。结果表明:多层AlN薄膜比单层AlN薄膜的吸收性能好;W比Al更适合做反射面材料,W-渐变型多层AlN膜系对太阳能的吸收率可达到80%以上。     

Optical property and cycling durability of polytetrafluoroethylene top-covered and metal buffer layer inserted Mg-Ni switchable mirror

Pd-capped Mg-rich Mg-Ni alloy thin film shows excellent reversible switching properties in optical transmittance by the exposure to hydrogen containing gas. However, it shows fast degradation due to the oxidization of magnesium and the switching durability is not good enough for practical applications. To resolve this problem we tried to improve its switching durability of Mg-Ni based switchable mirror by the combined use of metal buffer layer insertion between Pd and Mg-Ni layer and polytetrafluoroethylene (PTFE) protective coating. PTFE thin film has been prepared on the surface of Mg-Ni thin films by RF magnetron sputtering in the Ar and CF₄ mixed gas discharge plasma at room temperature and a power of 30 W. The sample of Pd/Ti/Mg₄Ni thin film with the protective coating of 900-nm-thick PTFE layer can be switched over 1600 switching cycles, which suppress the degradation by 15% of its initial transmission modulation level.     

All-solid-state thin film lithium batteries

薄膜型全固态锂电池具有完美的电极/电解质固-固界面,可以有效解决当前商用锂离子电池的安全性问题,并具有超长的循环寿命、较宽的使用温度范围、较低的自放电率等优点,相比体型固态锂电池性能优越,受到了业界的广泛关注。然而制备成本高、单位面积能量密度低等缺点限制了其应用范围。本文介绍了薄膜型全固态锂电池的工作原理及特点、关键材料的研究现状,并针对薄膜固态锂电池的产业化现状和技术瓶颈进行了总结,对新一代薄膜型全固态锂电池的发展及产业化应用进行了展望。     

a-Si∶H薄膜的再结晶技术发展概述

论述了非晶硅薄膜的主要再结晶技术,包括传统的炉子退火、金属诱导晶化、微波诱导晶化、快速热退火和激光晶化。着重指出了各种晶化技术已取得的研究成果、优缺点、有待进一步研究的内容及其在多晶硅薄膜太阳电池工业生产中的应用前景。     

GROWTH OF HETEROEPITAXIAL CdTe LAYERS ON REUSABLE Si SUBSTRATES AND A LIFT-OFF TECHNIQUE FOR THIN FILM SOLAR CELL FABRICATION

Heteroepitaxial (111) and (100) oriented CdTe layers have been grown on Si substrates by conventional molecular beam epitaxy (MBE) and photo-assisted MBE (PAMBE) using stacked BaF₂-CaF₂ as a buffer to overcome the 19% lattice mismatch between Si and CdTe. Heteroepitaxial As doped p-type CdTe(lOO) layers have been grown on BaF₂-CaF₂/Si(100). The dopant activation is accomplished using an extra Cd source and laser illumination of the substrate during growth. The growth kinetics and surface reconstructions have been studied using RHEED during CdTe growth under different conditions, and the induced effects on Te-desorption, Cd-migration, and As-substitution on Te-vacancy site have been correlated. The resistivity of As doped CdTe layers is down to 20 ohm cm. The 8 K photoluminescence spectra of such a layer shows a dominant (A^°, X) peak at 1.590 eV and the As acceptor level corresponds to a shallow level with = 60 me V activation energy. A lift-off technique has been used to separate the single crystal CdTe thin films from the Si wafer by dissolving the fluoride buffer. CdS/CdTe solar cells have been fabricated in these layers.     

Properties of ZnO thin films prepared by reactive evaporation

Non-doped ZnO thin films with suitable characteristics to be used as transport contact and as buffer layer in solar cells, were prepared by reactive evaporation. Through a parameter study, it was found that the main deposition parameters affect the optoelectrical properties of the ZnO films, being the oxygen partial pressure the parameter which most affects both, the transmittance and the conductivity. Actually, high-conductive ZnO films with blue transmittances greater than 80% are routinely prepared by using oxygen partial pressures greater than 0.2 mbar and evaporation temperatures of Zn about 540°C. AFM measurements revealed that the high values of blue transmittance obtained with ZnO film deposited at high O₂ – partial pressure are in part controlled by morphological effects. From Hall coefficient and conductivity measurements it was found that the conductivity is dominated by the resulting carrier concentration which is controlled by oxygen vacancies. The conditions to prepare in situ the double low ρ-ZnO/high ρ-ZnO bilayer structure regularly used in the fabrication of CdS-free, thin films solar cells, were also found through this study.     

Photoelectrochemical investigations on electrochemically deposited CdSe and Fe-doped CdSe thin films

Thin films of CdSe and Fe-doped CdSe (Fe:CdSe) were deposited onto stainless steel substrates by electrodeposition technique. The photoelectrochemical investigations have been carried out using the cell configurations CdSe/1 M (Na₂S–S–NaOH)/C and Fe:CdSe/1 M (Na₂S–S–NaOH)/C for studying the current–voltage (I–V) characteristics in dark and under illumination, photovoltaic output, spectral response, photovoltaic rise and decay characteristics. The studies reveal that films are n-type conductivity. The junction quality factor in light (n_l), series and shunt resistance (R_s and R_sh), fill factor (FF) and efficiency (η) for the cell have been estimated. After Fe doping, efficiency and FF of PEC solar cell is found to be improved from 0.34% and 31.12 to 1.80% and 35.78, respectively.     

Investigation of semiconducting parameters of Pb---Sn alloy oxide-electrolyte interface by Butler Gartner model

The effect of Sn doping on the photoactivity of anodized Pb---Sn alloy electrodes is discussed. The Butler-Gartner model has been applied to understand the reasons for getting the highest photocurrent with pure lead oxide and the next highest photocurrent with a Pb---Sn alloy oxide containing 0.1 wt.% Sn. The low photoresponse of Sn doped lead oxide is attributed to creation of a small space charge width (5600Å) compared to the large penetration depth (97,000Å) of the incident light.     

Investigation of semiconducting parameters of PbSn alloy oxide-electrolyte interface by Butler Gartner model

The effect of Sn doping on the photoactivity of anodized PbSn alloy electrodes is discussed. The Butler-Gartner model has been applied to understand the reasons for getting the highest photocurrent with pure lead oxide and the next highest photocurrent with a PbSn alloy oxide containing 0.1 wt.% Sn. The low photoresponse of Sn doped lead oxide is attributed to creation of a small space charge width (5600Å) compared to the large penetration depth (97,000Å) of the incident light.