共轭聚合物受体光伏材料和全聚合物太阳电池

全聚合物太阳电池(all-PSCs)由p-型共轭聚合物给体和n-型共轭聚合物受体共混活性层夹在ITO透明电极和金属顶电极之间所构成,除具有一般有机太阳电池器件结构简单、质量轻、可以制备成柔性和半透明器件等优点外,还具有形貌和光照稳定性好及抗弯折性能高等突出特点,最近成为有机太阳电池领域的研究热点.给体和受体光伏材料的吸...     

有机薄膜太阳能电池

有机太阳能电池作为一种新兴的有着巨大潜力的光电转换器件,吸引了越来越多的关注。综述了有机薄膜太阳能电池主要的两种器件结构的研究进展,即基于无机异质结发展出来的双异质结型有机太阳能电池和基于扩展双层异质结活性层受限的接触面积而提出的体异质结型太阳能电池;阐述了这两种器件结构的工作原理、影响有机太阳能电池光电转换效率的因素以及两种结构的不足之处,并展望了有机太阳能电池发展的广阔前景。     

顺序加工有机光伏器件的相分离及结晶性调控

活性层形貌对有机光伏器件性能有重要影响, 在本体异质结( BHJ)结构中, 活性层微观形貌复杂, 难以精确调控.相比之下, 顺序加工P-i-N结构可以单独加工给/受体, 使得形貌调控更简单易行.然而, 目前顺序加工形貌优化的相关机理研究相对缺乏, 不利于其在大面积器件中的应用.基于此, 采用顺序刮涂制备了基于PM6/Y...     

CuPc/C60薄膜太阳能电池的制备及膜厚对其光电性能的影响

本文采用CuPc作为电子给体,C60作为电子受体制备了ITO/CuPc/C60/Al异质结太阳能电池。实验表明器件中活性层(CuPc/C60)对太阳能电池的光电性能有很大的影响。主要原因是有机物的激子扩散长度大约是十几纳米左右,产生的激子大多数在未到达异质结之前就已经复合。本文讨论了活性层(CuPc/C60)的厚度比,并获得其最优比例。     

消息报道

正国家纳米科学中心有机太阳电池研究取得重要突破有机太阳电池因为其柔性、轻质、可溶液加工等特点而具有巨大商业应用前景。有机太阳电池活性层通常为二元体系,由一个电子给体和一个电子受体组成,给/受体共混形成纳米尺度互穿网络结构,可提供足够激子解离界面和载流子快速传输通道。由于有机共轭分子有限的光吸收,二元活性层吸光范围较窄,不能充分覆盖太阳辐射光谱。近年来,利用吸收互补的三种材料(如:     

无真空、低成本Mist-CVD外延制备高质量单晶NiO/Ga2O3 p-n异质结与器件(英文)

在氧化镓(Ga₂O₃)材料p型掺杂困难的背景下,Ga₂O₃ p-n异质结器件在氧化镓器件的应用中起着重要作用.因此,寻找一种高效、经济的制备方法制备Ga₂O₃异质结对器件应用具有重要意义.在这项工作中,我们成功基于低成本、无真空的雾化学气相沉积(Mist-CVD)外延制备了单晶氧化镍(NiO)和β-Ga₂O₃异质结.其中,NiO(111)和β-Ga₂O₃(-201)的XRD摇摆曲线半高宽分别为0.077°和0.807°.NiO与β-Ga₂O₃之间的能带表现为Ⅱ型异质结构.基于此异质结,我们制备了准垂直器件,器件具有明显的p-n结整流特性,反向击穿电压为117 V.本工作为β-Ga₂O₃异质p-n结的制备提供了一种低成本、高质量的方法.     

SiGe/Si异质结光电器件

SiGe/Si异质结光电器件及其光电集成(OEIC)是硅基光电研究的一个非常引人注目的领域.综述了SiGe/Si异质结材料的基本性质,SiGe/Si异质结光电器件的结构、性能、应用及其光电集成.重点介绍了SiGe/Si光电探测器及其与其他相关器件的集成.     

共轭长度增加的非富勒烯稠环受体在有机太阳能电池中的应用

文中合成了一种拥有更长共轭长度的新的稠环小分子IDT-2T-IC,并作为非富勒烯受体用于聚合物太阳能电池(PSCs)。其热力学性质、吸光特性及电化学性能被详细表征。该材料在300~850nm波长范围内有宽的吸收,同时还显示了较强的聚集趋势。将该材料作为电子受体,与聚合物给体PTB7-Th共混制备本体异质结(BHJ)太阳能电池,在对器件优化后,电池的能量转换效率(PCE)达到2.17%。     

基于无序堆积的呋喃类液晶小分子的高效有机光伏器件（英文）

将具有高迁移率和强分子间作用的液晶小分子引入有机光伏器件活性层中被认为是一种提升光电转换效率的有效策略.不同于常规的认识,本文展示了“弱结晶材料同样能优化活性层形貌和提升光伏器件效率”的三元有机光伏器件调控新策略.本文设计合成了两个基于苯并二呋喃给体单元的液晶小分子Z1和Z2,发现具有无序堆积特性的Z2基三元有机光伏器件展现出了更高的光电转换效率(Z2:PM6:BTP-eC9,PCE:18.12%; Z2:PM6:Y6, PCE:17.66%)和更优异的器件稳定性.而基于高度有序的Z1的三元有机光伏器件却表现出明显降低的能量转换效率.光电器件和活性层薄膜形貌的协同表征说明Z2基三元体异质结薄膜的高光电效率主要归因于其更优的电荷传输效率和更合适的相分离尺度.该研究工作展示的有机光伏器件第三组分的调控新策略对新型高效光伏器件的制备具有重要的指导意义.     

有机-无机杂化体异质结太阳电池研究现状

有机-无机杂化体异质结太阳电池以无机半导体纳米晶作为电子受体,共轭聚合物作为电子给体,是近年来的一个研究热点。在设计上,有机-无机杂化材料兼具有机材料的柔性、结构多样性、易加工和无机材料载流子迁移率高、稳定性好的优势,具有良好的发展前景。介绍了有机-无机杂化体异质结太阳电池的结构、工作原理,从共轭聚合物、无机半导体纳米材料以及电池制备工艺3个方面综述了近年来国内外研究现状,主要包括有机-无机杂化体异质结太阳电池中常用共轭聚合物结构、带隙,无机纳米晶种类、形貌、表面改性以及有源层厚度、形貌调控等内容。着重介绍了基于CdSe、TiO2、PbS类纳米晶的太阳电池。最后讨论了有机-无机杂化体异质结太阳电池目前存在的问题和发展方向。     

Ternary System with Controlled Structure: A New Strategy toward Efficient Organic Photovoltaics

Recently, a new type of active layer with a ternary system has been developed to further enhance the performance of binary system organic photovoltaics (OPV). In the ternary OPV, almost all active layers are formed by simple ternary blend in solution, which eventually leads to the disordered bulk heterojunction (BHJ) structure after a spin‐coating process. There are two main restrictions in this disordered BHJ structure to obtain higher performance OPV. One is the isolated second donor or acceptor domains. The other is the invalid metal–semiconductor contact. Herein, the concept and design of donor/acceptor/acceptor ternary OPV with more controlled structure (C‐ternary) is reported. The C‐ternary OPV is fabricated by a sequential solution process, in which the second acceptor and donor/acceptor binary blend are sequentially spin‐coated. After the device optimization, the power conversion efficiencies (PCEs) of all OPV with C‐ternary are enhanced by 14–21% relative to those with the simple ternary blend; the best PCEs are 10.7 and 11.0% for fullerene‐based and fullerene‐free solar cells, respectively. Moreover, the averaged PCE value of 10.4% for fullerene‐free solar cell measured in this study is in great agreement with the certified one of 10.32% obtained from Newport Corporation.     

11.2% All‐Polymer Tandem Solar Cells with Simultaneously Improved Efficiency and Stability

All‐polymer solar cells (all‐PSCs) that contain both p‐type and n‐type polymeric materials blended together as light‐absorption layers have attracted much attention, since the blend of a polymeric donor and acceptor should present superior photochemical, thermal, and mechanical stability to those of small molecular‐based organic solar cells. In this work, the interfacial stability is studied by using highly stable all‐polymer solar cell as a platform. It is found that the thermally deposited metal electrode atoms can diffuse into the active layer during device storage, which consequently greatly decreases the power conversion efficiency. Fortunately, the diffusion of metal atoms can be slowed down and even blocked by using thicker interlayer materials, high‐glass‐transition‐temperature interlayer materials, or a tandem device structure. Learning from this, homojunction tandem all‐PSCs are successfully developed that simultaneously exhibit a record power conversion efficiency over 11% and remarkable stability with efficiency retaining 93% of the initial value after thermally aging at 80 °C for 1000 h.     

Naphthalenediimide (NDI) polymers for all-polymer photovoltaics

Naphthalenediimide (NDI) polymers are an important class of electron-accepting (acceptor or n-type) semiconductors for organic photovoltaic (OPV) or organic solar cell (OSC) applications. Blending them with compatible electron-donating (donor or p-type) polymers yields an OPV device known as bulk-heterojunction (BHJ) all-polymer solar cells (all-PSCs). Compared to the more extensively studied OPVs using fullerene derivatives as the acceptor material, all-PSCs provide important benefits such as chemical tunability, mechanical flexibility and ambient/stress stability. Through an extensive research on materials design and device optimization in the last five years, all-PSCs employing NDI-based polymers have achieved remarkable improvement in device power conversion efficiency (PCE), now surpassing 10% – a number that approaches the state-of-the-art organic photovoltaic (OPV) cells using fullerenes. In this review, recent development of NDI-based conjugated polymers used in all-PSCs will be highlighted.     

Enhanced performance of P3HT/TiO2 bilayer heterojunction photovoltaic device having gold nanoparticles in the donor layer

The photovoltaic effects of blending gold nanoparticles (AuNPs) into the donor layer of a poly(3-hexylthiophene) (P3HT)/TiO2 bilayer heterojunction device have been studied. P3HT was synthesized via the modified Gragnard metathesis method and AuNPs with sizes ranging from 12 to 15 nm were formed via a reduction of HAuCl4. The blending of AuNPs into P3HT caused a lower photoluminescence (PL) intensities and a decreased energy level of the highest occupied molecular orbital (HOMO) than the pristine P3HT owing to the good electron-accepting nature of AuNPs. Upon the use of P3HT-AuNPs as the donor layer, the decreased HOMO(donor) resulted in an increased open circuit voltage (V(OC)) and thus enabled the fabricated (P3HT-AuNPs)/TiO2 bilayer heterojunction photovoltaic device to have an improved power conversion efficiency of solar energy. V(OC) as well as the overall power conversion efficiency increased with an increase in the AuNP content as a result of additional interfaces which facilitated the charge separation of excitons and percolation pathways which enhanced the electron transfer to the TiO2 acceptor. Furthermore, unannealed P3HT-AuNPs exhibited nanoholes and provided photovoltaic devices a power conversion efficiency nearly two time higher than annealed P3HT-AuNPs.     

Solution-processed organic solar cells from dye molecules: an investigation of diketopyrrolopyrrole:vinazene heterojunctions

Although one of the most attractive aspects of organic solar cells is their low cost and ease of fabrication, the active materials incorporated into the vast majority of reported bulk heterojunction (BHJ) solar cells include a semiconducting polymer and a fullerene derivative, classes of materials which are both typically difficult and expensive to prepare. In this study, we demonstrate that effective BHJs can be fabricated from two easily synthesized dye molecules. Solar cells incorporating a diketopyrrolopyrrole (DPP)-based molecule as a donor and a dicyanoimidazole (Vinazene) acceptor function as an active layer in BHJ solar cells, producing relatively high open circuit voltages and power conversion efficiencies (PCEs) up to 1.1%. Atomic force microscope images of the films show that active layers are rough and apparently have large donor and acceptor domains on the surface, whereas photoluminescence of the blends is incompletely quenched, suggesting that higher PCEs might be obtained if the morphology could be improved to yield smaller domain sizes and a larger interfacial area between donor and acceptor phases.     

Organic photovoltaic films

Organic electronic materials are of interest for future applications in solar cells. Although results for single layer organic materials have been disappointing, high photocurrent quantum efficiencies can be achieved in composite systems including both electron donating and electron accepting components. Efficiencies of over 2% have now been reported in four different types of organic solar cell. Performance is limited by the low red absorption of organic materials, poor charge transport, and low stability. These problems are being tackled by the synthesis of new materials, the use of new material combinations, and optimisation of molecular design, self assembly and processing conditions to control morphology. Power conversion efficiencies of over 5% are within reach, but the fundamental physics of organic donor–acceptor solar cells remains poorly understood. Within the last 18 months, power conversion efficiencies of over 2% have been achieved in four different types of organic solar cells. All are composite systems including electron donating and electron accepting components. Performance is limited by weak absorption in the red, poor charge transport, and low stability, but improvements are available through optimisation of materials and device structures.     

Enhancing Performance of Large‐Area Organic Solar Cells with Thick Film via Ternary Strategy

Large‐scale fabrication of organic solar cells requires an active layer with high thickness tolerability and the use of environment‐friendly solvents. Thick films with high‐performance can be achieved via a ternary strategy studied herein. The ternary system consists of one polymer donor, one small molecule donor, and one fullerene acceptor. The small molecule enhances the crystallinity and face‐on orientation of the active layer, leading to improved thickness tolerability compared with that of a polymer‐fullerene binary system. An active layer with 270 nm thickness exhibits an average power conversion efficiency (PCE) of 10.78%, while the PCE is less than 8% with such thick film for binary system. Furthermore, large‐area devices are successfully fabricated using polyethylene terephthalate (PET)/Silver gride or indium tin oxide (ITO)‐based transparent flexible substrates. The product shows a high PCE of 8.28% with an area of 1.25 cm² for a single cell and 5.18% for a 20 cm² module. This study demonstrates that ternary organic solar cells exhibit great potential for large‐scale fabrication and future applications.     

Preparation and characteristics of hybrid ZnO-polymer solar cells

We demonstrate a hybrid solar cell which was made by blending nanocrystalline ZnO (nc-ZnO) and conjugated polymer regioregular poly(3-hexylthiophene) (P3HT) as the active layer of the solar cell. It can be seen that the efficiency of this new type of solar cells obviously varied as the size and morphology of ZnO nanostructures. The short-circuit photocurrent, fill factor, and power conversion efficiency were enhanced while the smaller nc-ZnO was utilized in such a device.     

Enhanced light harvesting from Först-type resonance energy transfer in the quasi-solid state dye-sensitized solar cells

The demonstrated F?rst-type resonance energy transfer (FRET) is demonstrated in quasi-solid type dye-sensitized solar cells between organic fluorescence materials as an energy donor doped in polymeric gel electrolyte and a ruthenium complex as an energy acceptor on the surface of TiO2. Strong spectral overlap of emission/absorption of the energy donor and acceptor is required to obtain high FRET efficiency. The judicious choice of the energy donor allows the enhancement of the light harvesting characters of the energy acceptor (N3) in quasi-solid dye sensitized solar cells which increases the power conversion efficiency by 25% compare to that of a pristine cell. The optimized cell architecture fabricated with the quasi-solid type electrolyte containing fluorescence materials shows a maximum efficiency of 5.08% with a short-circuit current density (J(sc)) of 12.63 mA/cm2, and an open-circuit voltage (V(oc)) of 0.70 V under illumination of simulated solar light (AM 1.5, 100 mW/cm2).     

Controlled phase separation for efficient energy conversion in dye/polymer blend bulk heterojunction photovoltaic cells

Low-cost photovoltaic energy conversion using conjugated polymers has achieved great improvement due to the invention of organic bulk heterojunction, in which the nanoscale phase separation of electron donor and acceptor favors realizing efficient charge separation and collection. We investigated the polymer photovoltaic cells using N, N′-bis(1-ethylpropyl)-3,4,9,10-perylene bis(tetracarboxyl diimide)/poly(3-hexyl thiophene) blend as an active layer. It is found that processing conditions for the blend films have major effects on its morphology and hence the energy conversion efficiency of the resulting devices. By optimizing the processing conditions, the sizes of donor/acceptor phase separation can be adjusted for realizing efficient charge separation and collection. The overall energy conversion efficiency of the photovoltaic cell processed with optimized conditions increases by nearly 40% compared to the normally spin-coated and annealed cell.