NiSe纳米材料合成及其在染料敏化太阳能电池中的应用

探寻电催化性能优异、廉价的对电极材料是染料敏化太阳能电池发展过程中所面临的重大挑战之一。本文将采用一步溶剂热法合成NiSe纳米材料,采用喷涂法制备Ni Se薄膜,并作为染料敏化太阳能电池对电极。利用循环伏安曲线、塔菲尔极化曲线、电化学阻抗谱表征对电极的电催化性能。实验结果表明,在I–/I3~–体系中,Ni Se对电极展现出了与铂电极相当的电催化性能。通过染料敏化太阳能电池组装与测试,表明基于NiSe对电极的染料敏化太阳能电池拥有良好的光伏性能,其能量转换效率达到5.27%,与基于铂电极的电池效率(5.34%)相当。     

SILAR次数对In掺杂CdS量子点敏化太阳电池的影响

以In掺杂CdS量子点太阳能电池为例,讨论了SILAR次数对In掺杂CdS量子点敏化太阳能电池性能的影响。通过SEM、EDS、IPCE、紫外吸收光谱、J-V曲线、EIS等实验测试结果表明,当In掺杂CdS的摩尔比固定在1:5时,随着SILAR次数的增加,电池的短路电流密度、开路电压和光电转换效率都随着增加,当SILAR次数为6次时,In掺杂CdS的QDSCs光电转化效率达到了最大值(η=0.76%)。随着SILAR次数的继续增加,其光电转换效率将会下降。     

基于硫化镍的染料敏化太阳能电池光伏性能研究

在典型的染料敏化太阳能电池中，基于铂金属的对电极用于收集外电路的电子，并催化氧化态电解质还原。然而，由于铂金属为贵金属，因此需要开发廉价材料的对电极，从而降低生产成本。低温沉积法是一种简单的制备方法，它的主要优点是，在不需要高温加热的条件下，可以直接在导电衬底上沉积，制备出拥有优异催化性能的硫化镍薄膜，然后直接用作染料敏化太阳能电池的对电极。结果显示，基于硫化镍薄膜对电极的染料敏化太阳能电池的最佳光电转换效率为6.12%，这与基于铂对电极的染料敏化太阳能电池的转换效率(6.16%)非常接近。上述实验结果表明低温沉积法制备的硫化镍薄膜具有优异的电催化性能，有利于染料敏化太阳能电池的光伏性能提升。     

酞菁染料ZnPc和Q-PbS复合敏化纳米晶ZnO薄膜电极的研究

利用溶胶-凝胶旋涂镀膜法结合热处理工艺在FTO玻璃上制备了ZnO薄膜,并通过X射线衍射(XRD)、扫描电子镜(SEM)对其晶相及表面形貌进行了表征;以酞菁染料ZnPc和窄禁带半导体PbS量子点(Q-PbS)为敏化剂,分别制备了FTO/ZnO/ZnPc电极、FTO/ZnO/Q-PbS电极和FTOZnO/Q-PbS/ZnPc电极,结果表明,ZnPc和Q-PbS对ZnO纳米颗粒膜产生了良好的敏化作用,且两者的复合敏化效果最好;制备了FTO/ZnO/Q-PbS/ZnPc为光阳极的染料敏化太阳能电池(DSSC),在模拟太阳光下,电池的开路电压为304mV,短路电流为1.42mA,光电转换效率为0.696%,填充因子为0.348。     

酰化黑枸杞染料光谱分析及其光电性能的研究

目前染料敏化太阳能电池的天然染料主要以花青 素为主,但花青素敏化太阳能电池的 光电转换效率比较低。本研究从黑枸杞中提取花青素,利用阿魏酸、草酸和咖啡酸对黑枸杞 染料进行酰化改性,并将其作为敏化剂组装染料敏化太阳能电池。利用紫外-可见吸收光谱 , 循环伏安测试对染料的光谱吸收特性及光电性能进行了表征。结果表明:黑枸杞经酰化后光 谱范围有效扩宽,酰化黑枸杞染料均能将电子注入到TiO₂导带边缘,并且咖啡酸酰化后的 光吸收效率最大。在100 mW/cm²入射光照下,黑枸杞经酰化后光电 转换效率提高,其中咖 啡酸酰化后光电转换效率最大为1.01%。采用电化学阻抗进一步分析 电子在电池界面的传 输,酰化黑枸杞染料能够有效的抑制TiO₂与离子电解液之间的复合率。     

水热法制备TiO2纳米晶薄膜的光电性能研究

利用水热法制备了纳米TiO2粉体,分别利用该粉体和经过氢氧化钠溶液水热处理后的粉体涂覆在导电玻璃上制备成薄膜,然后组装为染料敏化太阳能电池.利用XRD和SEM对该薄膜进行表征,并用I-V测试仪对电池的光电性能进行研究.结果表明:未经处理的粉体制备的薄膜粒径小,分布均匀,为纯锐钛矿晶型,组装的电池光电转化效率为4.09%...     

CdSe@CdTe核壳II型量子点掺杂的薄膜太阳能电池

采用胶体化学法制备了CdSe@CdTe核壳量子点,将其置于CdTe量子点层与CdSe量子点层间构筑了三层结构的全无机薄膜太阳能电池(ITO/CdTe/CdSe@CdTe/CdSe/Al),在电池制备过程中对量子点薄膜进行了退火处理。吸收光谱、荧光光谱及荧光寿命测试结果表明所制备的CdSe@CdTe量子点为典型的II型量子点。其光电转换性能测量结果表明所制太阳能电池具有高达0.48%的能量转换效率,这主要得益于三层量子点间能带能量的差异对电子与空穴的定向传输的促进以及退火工艺对薄膜结晶质量的改善。     

MgO/TiO2复合薄膜太阳能电池的性能

用sol-gel法和丝网印刷法制备多孔TiO2薄膜,溶液沉积法制备MgO/TiO2复合薄膜。研究了复合薄膜的表面形貌、断面结构、厚度等性能;组装电池,测定了电池的输出特性曲线。结果表明:MgO/TiO2复合薄膜表面平整,内部具有分布较为均匀的空隙,厚度约14μm;MgO薄膜的复合使染料敏化,敏化太阳能电池的开路电压从0.585V提高到0.659V,短路电流从2.057mA提高到2.348mA,从而使光电转换效率从2.24%提高到3.12%;并分析了MgO薄膜复合提高光电流响应的机理。     

Mn^(2+)掺杂CdS量子点敏化太阳电池的性能北大核心

采用连续式离子层吸附与反应(SILAR)法不仅成功制备出CdS量子点敏化的TiO2纳米晶光阳极,而且实现了Mn2+在CdS量子点晶格内部的可控掺杂。应用场发射扫描电子显微镜(FESEM)对电极的形貌进行了分析和表征。继而通过组装光伏电池研究Mn2+掺杂浓度与电池性能之间的关系。通过测量其紫外-可见吸收光谱及电流密度-电压(J-V)特性曲线考察电池性能随Mn2+掺杂量的变化规律。在研究中发现,掺杂适量的Mn2+有助于提高CdS/TiO2光阳极对可见光的吸收,进而增强太阳电池的能量转换效率。当Mn2+浓度为0.075 mmol/L时,量子点敏化太阳电池(QDSSC)的能量转换效率可达2.85%,较未掺杂的光阳极试样性能提高约50%。     

掺铈的YAG荧光粉的光谱下转换效应对单晶硅太阳能电池的影响

将掺有稀土元素铈（Ce）的钇铝石榴石（YAG:Ce）荧光粉应用于单晶硅太阳能电池,通过YAG:Ce荧光粉的下转换效应提高电池的转换效率。为了更准确地认识光谱下转换效应所起的作用,我们将掺有Ce的YAG:Ce荧光粉和不含Ce的YAG粉分别与单晶硅太阳能电池片进行封装,在反射率、外量子效率和转换效率方面进行测试比较,并对裸电池片和封装电池的性能进行了讨论分析。实验结果表明,纯粹由光谱下转换效应带来的作用能使单晶硅太阳能电池的转换效率提高0.35%,体现了YAG:Ce荧光粉对提高单晶硅太阳能电池转换效率带来的积极作用。     

Enhance the performance of quantum dot-sensitized solar cell by manganese-doped ZnS films as a passivation layer

To make quantum dot-sensitized solar cells (QDSSCs) more attractive, it is necessary to achieve higher power conversion efficiency. A novel Mn-doped ZnS has been successfully fabricated on CdS/CdSe quantum dots (QDs) by simple successive ion layer adsorption and reaction (SILAR) technique. The Mn-doped ZnS is used as a passivation layer in the QDSSCs. The performance of the QDSSCs was examined in detail using sulfide/polysulfide electrolyte with a Pt or copper sulfide (CuS) counter electrode. Here we demonstrated, the fabricated Mn-doped ZnS QDs shows an improved V_oc (0.65 V) compared to bare ZnS QDs (0.60 V). The QDSSC based on a photoanode with Mn-doped ZnS (10 wt% of Zn) shows higher J_sc (15.32 mA cm⁻²) and power conversion efficiency (4.18%) compared to the bare ZnS photoanode (2.90%) under AM 1.5 G one sun illumination. We explore the reasons for this enhancement and demonstrated that it is caused by improved passivation of the ZnS surface by Mn ions, leading to a lower recombination of photo-injected electrons with the electrolyte. The effect of Cu ions in ZnS has been investigated by UV–Vis spectra and current density–voltage analysis.     

CdS and PbS quantum dots co-sensitized TiO2 nanorod arrays with improved performance for solar cells application

In this paper, we report a novel CdS and PbS quantum dots (QDs) co-sensitized TiO₂ nanorod arrays photoelectrode for quantum dots sensitized solar cells (QDSSCs). TiO₂ film consisting of free-standing single crystal nanorods with several microns high and 90–100 nm in diameter were deposited on a conducting glass (SnO₂:FTO) substrate by hydrothermal method. Then CdS/PbS QDs were deposited in turn on TiO₂ nanorods by facile SILAR technique. The FTO/TiO₂/CdS/PbS, used as photoelectrode in QDSSCs, produced a light to electric power conversion efficiency (Eff) of 2.0% under AM 1.5 illumination (100% sun), which shows the best power conversion efficiency compared with single CdS or PbS sensitized QDSSCs. One dimension TiO₂ nanorod provides continuous charge carrier transport pathways without dead ends. The stepwise structure of the band edges favored the electron injection and the hole-recovery for both CdS and PbS layers in photoelectrode, which may gave a high electric power conversion efficiency. The facile preparation and low cost nature of the proposed method and structure make it has a bright application prospects in photovoltaic areas in the future.     

无镉的铜铟镓硒太阳电池关键膜层XPS及AFM分析

应用溅射后硒化法和原子层沉积法分别制备了无镉的铜铟镓硒电池关键膜层CIGS光吸收薄膜和ZnO缓冲层,着重对该两膜层进行XPS和AFM表面分析,得到比较理想的制备工艺条件,并结合其它检测方法:SEM、XRD及吸收光谱等,证明采用操作简便、成本低廉的该工艺能制备出无镉的铜铟镓硒电池。通过I-V测试结果,该电池有一定的光电转换效率。     

Nd2(S,Se, Te)3 Colloidal Quantum Dots: Synthesis,Energy Level Alignment,Charge Transfer Dynamics,and Their Applications to Solar Cells

Novel and less toxic quantum dot (QD) semiconductors are desired for developing environmentally benign colloidal quantum dot solar cells. Here, the synthesis of novel lead/cadmium‐free neodymium chalcogenide Nd₂(S, Se, Te)₃ QDs via solution‐processed method is reported for the first time. The results show that small‐bandgap semiconductor QDs with a narrow size distribution ranging from 2 to 8 nm can be produced, and the wide absorption band can be achieved by the redshift owing to the size quantization effect by controlling the initial loading of chalcogenide precursors. By analyzing the band structure of QDs and the energy level alignment between QDs and TiO₂, the influence of energy offset between the conduction band edges of QDs and TiO₂ on the charge transfer dynamics and photovoltaic performance of QD solar cells (QDSCs) is investigated. It is revealed that among the three types of QDs studied, Nd₂Se₃ QDSCs with the smallest energy offset exhibit the best performances and a decent power conversion efficiency of 3.19% is achieved. This work clearly demonstrates the promising potentials of novel rare earth chalcogenide quantum dots in photovoltaic applications.     

In和Te掺杂PbSe薄膜制备及其对薄膜光电性能的影响机制

采用中频磁控溅射技术制备了PbSeIn和PbSeTe两种掺杂PbSe薄膜, 并采用理论模拟与实际实验相结合的方法研究了In和Te两种元素的掺杂机制及其对薄膜性 能的影响。结果表明,In原子主要通过置换Pb原子的形式进行掺杂,而Te原子则主要置换 Se原子;与未掺杂PbSe薄膜相比,PbSeIn和PbSeTe两种薄膜的光电敏感性均有一定提高, 其中In掺杂PbSe薄膜的平均电阻变化率最高。这是由于In元素在PbSe薄膜禁带内形成深杂 质能级,提高非平衡载流子寿命所导致的。而PbSeTe薄膜的光电敏感性则与未掺杂PbSe薄 膜相近。     

In situ synthesis of CuS nano platelets on nano wall networks of Ni foam and its application as an efficient counter electrode for quantum dot sensitized solar cells

Herein, we report for the first time efficient CuS/nickel foam (NF) counter electrode for quantum dots-sensitized solar cells (QDSSCs) is fabricated using chemical bath deposition technique which can serve as a highly efficient CE for QDSSCs. These are characterized using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), current voltage and impedance spectroscopy. The CuS/NF and CuS/FTO films are investigated as a counter electrode (CE) in QDSSCs. The QDSSC based on CuS/NF CE achieves power conversion efficiency (PCE) of 4.93% accrediting to the high fill factor (FF) of 0.58, and the PCE is greater than that of CuS/FTO CE (4.27%) for TiO₂/CdS/CdSe/ZnS electrode, under the illumination of one sun (AM1.5, 100 mW cm⁻²). Electrochemical measurements testified that CuS/NF reveals high electro-catalytic activity towards polysulfide reduction, thus accelerating QDSSCs performance. Consequently, the CuS/NF is very capable as an efficient CE for QDSSCs. This procedure not only provides high electro catalytic activity but also an efficient scheme to be used in different applications such as flexible solar cells, fuel cells and supercapacitor.     

高品质三元CdxPb1-xSe量子点的制备与非线性光学性能研究

因为具有独特的量子效应,量子点一直受到诸多领域的广泛关注。为了研究CdxPb1-xSe三元量子点非线性特性,研究了高品质三元量子点的简便制备方法,在此基础上,进一步在532nm激光条件下利用Z-扫描技术研究了其非线性光学性能。结果表明,以制备的N-油酰基-吗啡啉为溶剂,采用改进一锅煮法成功地获得了大小均一、结晶良好的CdxPb1-xSe量子点;Cd0.5Pb0.5Se量子点的非线性吸收系数和非线性折射率分别为1.0110-9m/W和-1.110-10 esu,相比于CdSe二元量子点,体现出更加显著的非线性折射特性。因此,CdxPb1-xSe量子点在激光防护、光电开关等方面具有重要的潜在应用价值。     

ZnSe quantum dots sensitized electrospun ZnO nanofibers as an efficient photoanode for improved performance of QDSSC

In the present study, zinc selenide (ZnSe) quantum dots (QDs) with an average size of ~2.6 nm were prepared by hot injection method and used as a sensitizer onto the electrospun ZnO nanofibers using 3-mercaptapropionic acid as a linker agent. The optical absorption, photoluminescence and time-resolved photoluminescence (TRPL) studies for ZnSe sensitized ZnO NFs were performed to give insight about the improvement in optical properties. The performances of fabricated QDSSCs was examined in detail using cobalt sulfide (CoS) as a counter electrode and polysulfide redox couple (S²⁻/S_x²⁻) as an electrolyte. The ZnSe QDs sensitized ZnO nanofibers showed an appreciable improvement in short circuit current density (6.60 mA/cm²) with a maximum power conversion efficiency of 1.24% under 1 sun illumination of 100 mW/cm². This enhancement is mainly due to better light harvesting ability of ZnSe QDs and ZnO NFs, and lower recombination of photoinjected electrons with the polysulfide electrolyte. The improvement in power conversion efficiency (PCE) and reduction in back electrons recombination are supported by photovoltaic and electrochemical impedance studies. Finally, stability test was carried out over a span of 30 days (720 h) under one sun illumination to know about the practical applicability of the resultant QDSSC.     

分光谱太阳能光电转换系统研究

单种类光电子器件的光电响应特性难以获得与太阳能全光谱匹配的高效率光电转换,突破其物理限制的努力方向是研制高转换效率的“第三代”分光谱多结电池。在本工作中,采用分光谱技术,将太阳光谱分成4个子光谱区,分别为400－630nm;630－800nm;800-900nm;900-1800nm;与这些子光谱区的范围相对应,分别采用能隙值与子光谱区相匹配的4个不同种类的具有较高光电转换效率的高性能单结光电器件,实现将太阳光高效率转换成电能。在太阳能电池辐照测试的0.5－6.0个SUN(AM1.5G)变化条件下,对多光谱组合的太阳能电池的光电转换效率进行了测试,获得了在2.8个SUN(AM1.5G)辐照条件下37.7％的实测光电转换效率。在此基础上,给出了利用单结电池组合制备高效率组合型分光谱太阳能光电转换系统的途径,具有较低成本和实际推广应用价值。     

The photovoltaic performance of alloyed CdTexS1−x quantum dots sensitized solar cells

The photovoltaic performance of alloyed CdTe_xS_1−x quantum dots (QDs) sensitized solar cells (QDSSCs) as a function of tuning the band gap of alloyed CdTe_xS_1−x QDs is studied. The tuning of band gap was carried out through controlling the molar ratio (x) of QDs. Presynthesized alloyed CdTe_xS_1−x QDs of different x values (0, 0.2, 0.4, 0.6, 0.8, and 1) were deposited by direct adsorption (DA) technique onto a layer of TiO₂ nanoparticles (NPs) to serve as sensitizers for the solar cells. The characteristic parameters of the assembled QDSSCs were measured under AM 1.5 sun illumination, and show that CdTe_xS_1−x QDs has better photovoltaic performance than pure CdTe QDs or CdS QDs. The maximum values of J_sc (1.54 mA/cm²) and η (0.31%) were obtained for x=0.6. However, The open circuit voltages (V_oc) approximately constant (0.46±0.02 V) for all alloyed CdTe_xS_1−x QDSSCs. It is only dictated by the conduction band (CB) level of TiO₂ nanoparticles (NPs) and the valance band (VB) of the electrolyte.