空穴传输材料在高效钙钛矿太阳能电池中的发展演变

钙钛矿太阳能电池(PSCs)转换效率已从2009年的3.8%上升到2017年的22.7%,其快速的发展可能使光伏工业进入革命新阶段。空穴传输材料(HTM)是构成高效钙钛矿太阳能电池的重要组成部分,开发和设计导电性好、成本低、稳定性好的空穴传输层材料对钙钛矿太阳能电池的研究显得非常重要。本文将近几年应用于钙钛矿太阳能电池中较高效的空穴传输材料归纳为有机小分子类、有机聚合物类和无机材料类,同时也介绍了无空穴传输层的钙钛矿电池。详细评述了基于各类空穴传输材料的钙钛矿太阳能电池的光电性能及稳定性,重点讨论了HOMO能级、空穴迁移率、添加剂的掺杂等因素对钙钛矿太阳能电池的影响。最后指出了空穴传输材料未来的研究重点和发展趋势。     

钙钛矿太阳能电池空穴传输材料的研究进展

钙钛矿太阳能电池具有工艺简单、可弯曲、应用前景广阔等优点。从2009年出现起,至今其效率从3.8%提高到了22%以上,引起了研究者的广泛关注。介绍了钙钛矿太阳能电池的基本结构和工作原理,概述了钙钛矿太阳能电池空穴传输材料的研究进展,着重介绍了无机空穴传输材料的研究进展。最后展望了钙钛矿太阳能电池未来的发展与商业化应用。     

溶液法合成的功能无机材料氧化镍对钙钛矿太阳能电池光电性能的影响

功能无机材料氧化镍 （NiO_x） 作为钙钛矿太阳能电池中最有前途的空穴传输材料之一,其有着高空穴迁移率、良好的稳定性、易于加工以及适合的费米能级等优点。但是,由于 NiO_x自身固有电导率低,Ni空位的电离能相当大,未掺杂的 NiO_x中空穴密度受到很大限制,加上孔洞的积累增加了载流子复合的可能,从而降低了有效的电荷收集。因此,优化 NiO_x薄膜的成膜质量是解决上述问题的关键。本文通过溶液法使用乙二醇甲醚（MEA）、乙醇（EA）和去离子水作为溶液,分别制备了 DME-NiO_x、EA-NiO_x 和 NCs-NiO_x 薄膜,并在浓度调节范围内对基于 NiO_x的钙钛矿器件进行优化,最终得到了光电转化效率 （PCE） 为 18.50%,开路电压 (V_oc) 为 1.034 V,短路电流 (J_sc) 为 22.94 mA/cm²,填充因子 （FF） 为 78% ...     

倒置钙钛矿太阳能电池的空穴传输层的研究进展

倒置钙钛矿太阳能电池(PSCs)具有器件结构简单、吸光系数高、迟滞效应小、良好的缺陷容忍性等优点,受到了广泛的关注。但倒置器件光电转换效率(PCE)尚有待提高,究其原因是空穴传输层(HTL)和钙钛矿层界面处的能量损失表现出相对较小的开路电压。文章综述了包括有机聚合物、无机物、尖晶石氧化物等作为空穴传输材料的相关研究进展,进一步分析了通过调节电极/空穴传输层能级使之与钙钛矿价带匹配,及通过界面修饰促进器件对载流子的注入与收集,从而提高光电转换效率的研究现状。对提高倒置钙钛矿太阳能电池性能的研究具有一定的指导意义,最后对倒置器件的应用前景进行了展望。     

复合钙钛矿太阳能电池电荷传输层材料研究进展

有机无机复合钙钛矿太阳能电池因具有适合的载流子扩散长度而成为备受关注的有望获得高效率的光伏器件。复合钙钛矿材料本身不含贵金属元素,可以采用液相法或物理气相法低温制备,成本低廉,但目前应用最多的电子传输层材料TiO2需400~500℃煅烧,与柔性基底及低温制备技术适应性差;空穴传输层材料SpiroOMeTAD合成工艺复杂,价格高昂,限制了复合钙钛矿太阳能电池的开发应用。开发和研究导电性好、成本低、稳定性好的电子和空穴传输层材料是复合钙钛矿太阳能电池研究中的一个非常重要的方面。综述了复合钙钛矿太阳能电池中电荷传输层材料的研究进展及发展方向。电子传输层材料方面通过对TiO2的改性以及与石墨烯的复合,采用ZnO、石墨烯或PCBM作为电子传输层材料,以与柔性基底及低温制备技术相适应。空穴传输层材料方面,采用其它低成本、导电性高的有机p型半导体替代spiro-OMeTAD;采用无机空穴传输层材料以避免有机空穴传输层材料的老化问题,提高电池的长期稳定性;利用复合钙钛矿材料兼作吸收层与空穴传输层,制备无空穴传输层材料结构电池以降低成本,提高稳定性。     

基于氧化石墨烯空穴传输层的平面异质结钙钛矿太阳能电池

钙钛矿太阳能电池中传统空穴传输层Spiro-OMeTAD存在昂贵、易污染环境且制备困难等缺点,本工作采用氧化石墨烯(Graphene oxide,GO)作为空穴传输层,研究了不同浓度GO溶液制备的衬底对器件光电性能的影响.首先,采用旋涂法制备了GO薄膜,通过对分散液浓度的控制获得了不同厚度的GO衬底.其次,制备了结构为ITO/GO/CH3 NH3 PbI3/PCBM/Ag的平面型器件,对不同GO衬底的器件的光电性能进行表征及对比分析.研究表明:GO衬底缺陷会抑制CH3 NH3 PbI3晶粒的择优取向生长,形成可诱导CH3 NH3 PbI3晶粒产生横向聚集的籽晶,从而改善钙钛矿薄膜的成膜性,并增大钙钛矿晶粒尺寸.由浓度为0.25 mg/mL的分散液制备的GO薄膜衬底上生长的钙钛矿晶粒尺寸最大为900 nm.此外,该浓度对应的GO衬底上制备的钙钛矿薄膜的光致发光相对强度峰值为2000,电荷转移效率相对最高,为52.8％.由该衬底制备的GO基钙钛矿太阳能电池的光电转化效率最高可提升至8.69％.     

基于全无机CsPbBr3钙钛矿太阳能电池的光电性能研究

钙钛矿太阳能电池具有制作工艺简单和光电转换效率高等优点,成为光伏领域研究的热点.而全无机钙钛矿太阳能材料CsPbBr3具有较强的稳定性,是具有竞争力的钙钛矿光吸收材料.主要利用SCAPS-1D软件构建了 FTO/TiO2/CsPbBr3/Cu2ZnSnS4(CZTS)/Ag平面异质结结构.研究了全无机钙钛矿材料CsPbBr3厚度和带隙对钙钛矿太阳能电池的影响.     

锡铅混合钙钛矿太阳能电池垂直组分梯度的溶剂工程调控

带隙1.1～1.4eV的锡铅混合卤化物钙钛矿是单结太阳能电池光电转换效率(PCE)接近Shockley-Queisser(S-Q)理论效率极限值的理想材料。钙钛矿薄膜垂直方向上的化学组分梯度会通过影响能带结构影响载流子的传输和分离,因此对锡铅混合钙钛矿薄膜的结晶过程进行控制十分重要。本研究发现使用不同剂量的反溶剂制备锡铅混合钙钛矿会形成不同的垂直组分梯度,并且随反溶剂用量增大薄膜表面铅含量增加。调整溶剂组分可以控制锡铅混合钙钛矿的垂直组分梯度,增大溶剂中V(DMSO):V(DMF)可以形成底部富铅而表面富锡的垂直组分梯度。当铅基前驱液溶剂中V(DMSO):V(DMF)最优化为1:2时,相比于1:4的对照组,器件在标准光照条件下的开路电压从0.725V提高到0.769V,短路电流密度从30.95mA·cm^–2提高到31.65 mA·cm^–2,PCE从16.22%提升到接近18%。利用SCAPS软件数值模拟进一步证明了垂直组分梯度的必要性,当钙钛矿薄膜底部富铅、顶部富锡时,载流子在空穴传输层界面区域的复合有所减少,因而电池性能得到提升。     

反溶剂法制备高效平面异质结钙钛矿太阳能电池

在一步旋涂制备钙钛矿活性层的过程中,通过无/有溶剂氯苯的处理,探究反溶剂法制备的平面钙钛矿太阳能电池的光伏性能.利用SEM、XRD、J-V以及IPCE对对照组和反溶剂制备的钙钛矿薄膜和器件进行表征.结果表明反溶剂法获得的平面钙钛矿太阳能电池的光电转换效率高达16.05％,比对照组效率提高了31.44％.瞬态光电压的结果...     

铅卤钙钛矿太阳能电池界面工程的近期进展

铅卤钙钛矿太阳能电池因其优良的光电转换效率以及相对低廉的制备成本而受到广泛关注。然而铅卤钙钛矿太阳能电池的长期稳定性限制了其商业化的进程。界面非辐射复合导致铅卤钙钛矿太阳能电池产生能量损失、影响器件稳定性,是造成器件性能恶化的主要原因。界面工程作为一种有效的策略被用于抑制界面非辐射复合,在制备高效稳定的铅卤钙钛矿太阳能电池方面取得了切实的成效。本文阐述了铅卤钙钛矿太阳能电池的工作原理以及界面上的非辐射复合过程,分析了界面非辐射复合产生的原因,总结了近期n-i-p正式结构铅卤钙钛矿太阳能电池中界面工程的研究进展,讨论了其作用机制。基于目前铅卤钙钛矿太阳能电池中的界面工程发展现状,对其未来的发展方向进行了展望。     

Tailoring interface of lead-halide perovskite solar cells

Lead-halide perovskite solar cells (PSCs) have attracted tremendous attention during the past few years owing to their extraordinary electronic and photonic properties.To improve the performances of PSCs,many researchers have focused on the compositional engineering,solvent engineering,and film fabrication methodologies.Interfacial engineering of PSCs has become a burgeoning field in which researchers aim to deeply understand the mechanisms of cells and thereby increase the efficiency and stability of PSCs.This review focuses on the interface tailoring of lead-halide PSCs,including the modification of each layer of the cell structure (i.e.,perovskite absorber,electron-transport layers,and holetransport layers) and the interfacial materials that can be introduced into the PSCs.     

Recent progress in efficient hybrid lead halide perovskite solar cells

The efficiency of perovskite solar cells (PSCs) has been improved from 9.7 to 19.3%, with the highest value of 20.1% achieved in 2014. Such a high photovoltaic performance can be attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths of the hybrid lead halide perovskite materials. In this review, some fundamental details of hybrid lead iodide perovskite materials, various fabrication techniques and device structures are described, aiming for a better understanding of these materials and thus highly efficient PSC devices. In addition, some advantages and open issues are discussed here to outline the prospects and challenges of using perovskites in commercial photovoltaic devices.     

Recent progress in efficient hybrid lead halide perovskite solar cells

Abstract

The efficiency of perovskite solar cells (PSCs) has been improved from 9.7 to 19.3%, with the highest value of 20.1% achieved in 2014. Such a high photovoltaic performance can be attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths of the hybrid lead halide perovskite materials. In this review, some fundamental details of hybrid lead iodide perovskite materials, various fabrication techniques and device structures are described, aiming for a better understanding of these materials and thus highly efficient PSC devices. In addition, some advantages and open issues are discussed here to outline the prospects and challenges of using perovskites in commercial photovoltaic devices.     

碳材料在钙钛矿太阳能电池中的应用

钙钛矿太阳能电池具有材料成本低廉、生产工艺简单、光电转换效率高等优点,发展前景十分光明。碳材料因其价格低廉、高导电性、疏水性和化学稳定性等特点,被应用在钙钛矿太阳能电池的各个组成部分,用于提高电池性能和降低成本。本文根据应用在钙钛矿太阳能电池中的碳材料的维数进行分类,分别介绍了零维的C60、碳量子点和石墨烯量子点,一维的碳纳米管,二维的石墨烯及其衍生物、石墨炔和三维的石墨等在钙钛矿太阳能电池中的应用,对于将来实现钙钛矿太阳能电池的低成本商业化和大规模制造具有重要意义。     

Low-temperature processed solar cells with formamidinium tin halide perovskite/fullerene heterojunctions

A new type of lead-free, formamidinium (FA)-based halide perovskites, FASnI₂Br, are investigated as light-harvesting materials for low-temperature processed p–i–n heterojunction solar cells with different configurations. The FASnI₂Br perovskite, with a band-gap of 1.68 eV, exhibits optimal photovoltaic performance after low-temperature annealing at 75 °C. By using C₆₀ as electron-transport layer, the device yields a hysteresis-less power conversion efficiency of 1.72%. The possible use of an inorganic MoO _x film as a new type of independent hole-transport layer for the present tin-based perovskite solar cells is also demonstrated.

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Solution processed inorganic V<Subscript>2</Subscript>O<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> as interfacial function materials for inverted planar-heterojunction perovskite solar cells with enhanced efficiency

An inverted planar heterojunction perovskite solar cell (PSC) is one of the most competitive photovoltaic devices exhibiting a high power conversion efficiency (PCE) and nearly free hysteresis in the voltage–current output. However, the band alignment between the transport materials and the perovskite absorber has not been optimized, resulting in a lower open-circuit voltage (V _oc) than that of regular PSCs. To address this issue, we tune the band alignment in perovskite photovoltaic architecture by introducing bilayer structured transport materials, e.g., the hole transport material poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/V₂O₅. In this study, solution processed inorganic V₂O _x interlayer is incorporated into PEDOT:PSS for achieving improved film surface properties as well as optical and electrical properties. For example, the work function (WF) was changed from 5.1 to 5.4 eV. A remarkably high PCE of 17.5% with nearly free hysteresis and a stabilized efficiency of 17.1% have been achieved. Electronic impedance spectra (EIS) demonstrate a significant increase in the recombination resistance after introducing the interlayer, associated with the high V _oc output value of 1.05 V. Transient photocurrent and photovoltage measurements indicate that a comparable charge transport process and an inhibited recombination process occur in the PSC with the introduction of the V₂O _x interlayer.

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Dual function of a high-contrast hydrophobic-hydrophilic coating for enhanced stability of perovskite solar cells in extremely humid environments

In spite of a continuous increase in their power conversion efficiency (PCE) and an economically viable fabrication process,organic-inorganic perovskite solar cells (PSCs) pose a significant problem when used in practical applications:They show fast degradation of the PCE when exposed to very humid environments.In this study,the stability of PSCs under very humid conditions is greatly enhanced by coating the surface of the PSC devices with a multi-layer film consisting of ultrahydrophobic and relatively hydrophilic layers.A hydrophobic composite of poly(methyl methacrylate) (PMMA),polyurethane (PU),and SiO2 nanoparticles successfully retards the water molecules from very humid surroundings.Also,the hydrophilic layer with moderately PMMA captures the residual moisture within the perovskite layer;subsequently,the perovskite layer recovers.This dual function of the coating film keeps the PCE of PSCs at 17.3％ for 180 min when exposed to over 95％ humidity.     

Moisture-driven phase transition for improved perovskite solar cells with reduced trap-state density

We report a mechanistic understanding of a moisture-driven intermediate-phase transition that improves the quality of perovskite thin films based on a lead-acetate precursor,improving the power-conversion efficiency.We clarify the composition of the intermediate phase and attribute the transition of this phase to the hygroscopic nature of the organic product,i.e.,methylammonium acetate.Thermal annealing aids in the coarsening of the grains.These decoupled processes result in better crystal formation with a lower spatial and energetic distribution of traps.Thermal annealing of the films without exposure to air results in a faster intermediate-phase transition and grain coarsening,which occur simultaneously,leading to disorder in the films and a higher deep trap-state density.Our results indicate the need for a humid environment for the growth of high-quality perovskite films and provide insight into intermediate-phase dissociation and conversion kinetics.Thus,they are useful for the large-scale production of efficient solution-processed perovskite solar cells.     

具有2D-EDAPbI4薄覆盖层的环境稳定的FAPbI3基钙钛矿太阳能电池（英文）

二维(2D)卤化铅钙钛矿材料是钙钛矿太阳能电池(PSC)中最有前途的吸光材料之一,具有优异的稳定性和缺陷钝化作用.然而,这些稳定的二维PSC的转换效率仍远远落后于三维钙钛矿电池.在本文中我们通过原位生长的方法将2D EDAPbI4层成功制备在3D FAPbI3层表面。这种合理设计的2D-3D钙钛矿薄膜分层结构可以明显提高电池的效率.另外,由于EDAPbI4层的高抗湿性和抑制迁移, 2D-3D电池器件显示出明显增强的长期稳定性,在200 h内一直保持初始转换效率,甚至在500 h后仍能保持其初始转化效率的90%.     

基于有机金属卤化物钙钛矿材料的全固态太阳能电池研究进展

作为太阳能电池的光吸收剂,有机金属卤化物钙钛矿材料不仅具有高效的光吸收能力和载流子迁移率,还具有独特的双极性特征,能同时传输电子和空穴,使其成为优异的光伏材料,掀起了基于钙钛矿材料太阳能电池的研究热潮。介绍了近几年来基于有机金属卤化物钙钛矿材料的全固态太阳能电池的发展情况,总结了有机金属卤化物钙钛矿材料的结构和特性,对目前几类典型的钙钛矿太阳能电池进行了讨论,并展望了全固态钙钛矿太阳能电池的产业化应用前景。