Sulfides as a new class of stable cost-effective materials compared to organic/inorganic hole transport materials for perovskite solar cells

Perovskite solar cells (PSCs) have received a remarkable attention compared to the other types of solar cells due to their high carrier mobility, low recombination rate, and rapid increase in terms of efficiency in short time. However, two essential parameters being stability and cost are still challenging with these kinds of solar cells. Hole transport materials (HTMs) play an important role in PSCs as they can be effective in the charge transportation, determining the device stability and having a large share of cell costs, and overall resulting in the enhancement of open-circuit voltage (V_oc), short-circuit current (J_sc), and fill factor (FF). In addition to the organic HTMs which are widely used in PSCs, various inorganic HTMs mainly divided into the oxide and sulfide subgroups, have been developed in order to improve both stability and cost of PSCs. Herein, we provide an overview of the diverse types of HTMs, from organic to inorganic, especially oxide and sulfide inorganic HTMs and investigate the physical properties, synthesis, and their applications in various PSCs for both mesoporous and planar structure in the hope of encouraging further research and the optimization of these materials.     

有机光电高分子材料研究热点和前沿分析

基于基本科学指标数据库（ESI）的高被引论文,通过热点文献、CiteSpace分析工具得到的热点关键词对应的文献分析,得出有机光电高分子材料主要关注点为有机太阳能电池。有机太阳能电池的研究热点为：高性能活性层材料的设计合成;高性能界面材料的设计合成及其界面调控性能的研究;电池器件中有机半导体活性层表界面的可控掺杂;有机太阳能电池活性层能量损失研究。通过高被引论文的共被引分析,关键词突变探测技术和算法对词频的变动趋势分析,得出有机光电高分子领域最新关注前沿：高效太阳能电池的制备;非富勒稀受体的研究;有机半导体材料的设计合成;结构-性能研究;加工及应用性能。有机光电高分子材料研究活跃的前沿领域：高效全聚合物太阳能电池;三元有机太阳能电池;高效的倒置型太阳能电池;超高迁移率的透明有机薄膜晶体管;高迁移率场效应晶体管;二维共轭聚合物;聚合物半导体等。有机太阳能电池研究前沿主题演化趋势：从聚噻吩给体体系——新型给体-受体体系;单层——双层——本体异质结电池结构;富勒烯受 体——非富勒烯受体;高效及稳定性器件发展。本文创新性地将文献计量分析方法同文献具体内容分析相结合,通过大量的高质量文献内容分析,使得出的研究热点和前沿更具体和接近实际情况,为相关科研人员提供有益参考。     

Quantum Cutting in Luminescent Glasses and Glass Ceramics

In the last decade, revolutions in photonic material design and large-area nanostructure fabrication have given researchers and technologists tools to enable a new era of ultrahigh-efficiency photovoltaics. Quantum cutting has received much attention as a potential approach to enhance the photovoltaic conversion efficiency of solar cell in the recent decades. In this article, we review the phenomena, mechanisms, and design of the quantum cutting processes, focusing on the promising applications of the transparent glasses and glass ceramic materials as the down-converter of solar spectrum. We discuss the gaps between the current theoretical analysis and the practical applications of the quantum-cutting materials. To concave the negative effects of using the quantum-cutting materials as a down-converter on the front surface of the solar cell, much attention should be given to the choice of material and improvement of the material properties as well as the integration of photonic nanostructures and circuits on the solar cell.     

Selenium-Containing π-Conjugated Polymers for Organic Solar Cells

Organic solar cell research has attracted scientific and commercial interest in the last decade due to a rapid increase in power conversion efficiencies (PCEs). Today, PCEs in the range of 8–10 % have been obtained using conjugated polymers as electron-donor materials in combination with fullerene/other acceptors. However, to enable commercial applications, the efficiencies and lifetimes of organic solar cells still need to be improved significantly. In recent years, due to the potential advantages of Se-containing conjugated materials, namely, lower band gaps, rigidity, and strong Se⋅⋅⋅Se integration, have attracted surprising attention for use in organic solar cells. In this review, we focus on the synthesis and applications of Se-containing conjugated polymers for organic solar cells and throughout compare them with S- and O-containing analogues where applicable. The relationships between the chemical structures and properties, such as absorptions, energy levels, mobilities, and photovoltaic behavior, are also discussed.     

有机太阳能电池材料近期进展（上）

综述了近年来有机太阳能电池材料的研究进展     

有机太阳能电池材料近期进展（下）

综述了近年来有机太阳电池材料的研究进展。     

Design Analysis of Heterojunction Solar Cells with Aligned AZO Nanorods Embedded in p-type Si wafer

Higher price-per-watt of silicon (Si) solar cells is still the main bottleneck in their widespread use for power generation due to their expensive manufacturing process. The n-type zinc oxide (n-ZnO) and p-type Si (p-Si) based single heterojunction solar cell is one of the several methods being tried to replace conventional Si single homojunction solar cell technology. In this work, we have explored the possibility of producing photovoltaic materials by employing RF sputtering and hydrothermal technologies. Conductivity of ZnO nanorods has been increased by aluminium (Al) doping. The advantages of using Al doped ZnO (AZO) nanorods (NRs) have been investigated. The integrated reflectance (IR) has been found to be only ~2.86%. Hence, the short circuit current density (Jsc) has been increased by minimizing the reflection loss of solar cells. AZO NR array have been developed over several large area (3″ × 3″) textured p-Si wafers to confirm the repeatability. The maximum efficiency of AZO NRs/Si solar cell of 0.8 cm2 area has been found to be 6.25% for textured p-type Si wafer which is much higher than reported hitherto for this type of solar cell. A simple, low temperature, low cost procedure is thus being proposed, which has the potential of attaining lower cost of production of heterojunction silicon solar cells.     

Recent Progress of Innovative Perovskite Hybrid Solar Cells

Recently, innovative perovskite hybrid solar cells have attracted great interest in solar cell research fields, such as dye-sensitized solar cells, organic photovoltaics, thin-film solar cells, and silicon solar cells, because their device efficiencies are gradually approaching those of crystalline Si solar cells, and they can be fabricated by cheap low-temperature solution processes. Here, we review the recent progress of innovative perovskite hybrid solar cells. The introduction includes the general concerns about solar cells and why we need innovative solar cells. The second part explains the structure and the material properties of hybrid perovskite materials. We focus on why the hybrid perovskite materials can exhibit excellent solar cell properties, such as high open-circuit voltage. The third part introduces recent progress in innovative perovskite hybrid solar cells, in terms of device architecture and deposition methods for dense perovskite thin films with full surface coverage. The device architecture is important in attaining high power conversion efficiency; the device operating mechanism is dependent on the device structure; and the pinhole-free dense perovskite thin films with full surface coverage are crucial for achieving high efficiency. Finally, we summarize the recent progress in perovskite hybrid solar cells, and the issues to be solved, in the summary and outlook section.     

Organic materials for organic electronic devices

In recent years, organic electronic devices which use organic materials as an active layer have gained considerable interest as light-emitting devices, energy converting devices and switching devices in many applications. In these organic electronic devices, the organic materials play a key role of managing the device performances and various organic materials have been developed to improve the device performances of organic electronic devices. In this paper, recent developments of organic electronic materials for organic light-emitting diodes and organic solar cells were reviewed.     

Carbon nanotube incorporation: A new route to improve the performance of organic–inorganic heterojunction solar cells

Incorporation of oxidized camphoric multi-walled carbon nanotubes (MWCNs) in the polymer layer of regioregular poly(3-octylthiophene)/n-Si heterojunction solar cell is observed to improve the performance of the device by many folds. We report power conversion efficiency, open circuit voltage, short-circuit current density, and fill factor of 0.175%, 0.22 V, 2.915 mA/cm², 0.27 respectively, for an un-optimized cell containing MWCNs. Reference cells without MWCNs show much lower performance. Improved device performance is due to better hole transport, easy exciton splitting and suppression of charge carrier recombination as a result of incorporation of MWCNs. MWCNs, being low cost materials, seem to be promising materials for improving device performance of organic–inorganic heterojunction solar cells.     

Recent trends in polymer tandem solar cells research

Polymer solar cells have many intrinsic advantages, such as their light weight, flexibility, and low material and manufacturing costs. Recently, polymer tandem solar cells have attracted significant attention due to their potential to achieve higher performance than single cells. This trend article intends to provide the latest progress in polymer tandem solar cell technology with a focus on active layer materials and interfacial materials for sub-cell interconnection. Following an introduction of the structure and current status of polymer tandem solar cells, this article will review polymers which have been, and could be used, for tandem solar cells. Furthermore, this article will discuss the interconnecting layer consisting of p- and n-type interfacial layers, which is equally critical for polymer tandem solar cells. Finally, because tandem solar cell measurements are more complicated than that of single solar cells, this article will also address polymer tandem solar cell measurement issues.     

Integrated Use of Solar Energy for Crop Drying

Various factors such as energy efficiency, the quality of end-products, and environmental aspects have to be taken into account during the drying of agricultural produce. During the recent past, several new approaches for the application of solar dryers to drying various biological materials were developed. In this paper, the background of solar drying, current solar drying practices, and drying of biological products such as grain, fruit, vegetables, hay, etc., are discussed. Additionally, an integrated energy/technology approach in order to maximize solar energy usage and thereby meet the drying requirements has been introduced. This will aid in achieving a sophisticated solution for drying process control, as well.     

柔性钙钛矿太阳能电池的制备及性能研究

采用钛箔作为衬底,原位生长二氧化钛薄膜,然后制备有机钙钛矿吸收层及固态空穴传输层,组装成太阳能电池。通过电压-电流曲线测试,结果表明,这种钙钛矿太阳能电池的光生电压达到0.8 V、光生电流达到16 mA/cm²、光电转化效率为10.2%。进一步对电池进行弯折试验,弯折20次后,光电转化效率能达到初始值的85%,表现出良好的柔性特征。     

染料敏化太阳能电池丝网印刷浆料中有机造孔剂对电池性能的影响

本文采用丝网印刷工艺制备染料敏化太阳能电池的氧化钛多孔薄膜,并将其组装成电池器件.主要研究了丝网印刷浆料中造孔剂-乙基纤维素和松油醇的含量对氧化钛薄膜光电性能的影响.光电性能测试和扫描电镜结果显示,当乙基纤维素N50和N10的比例为1:0、松油醇的含量为75%时,薄膜的结构和光电转换性能结果最优,单层光电转换效率从0.84%提升到1.23%.     

Eosin-G and ethyl eosin dye sensitized CdS nanowires towards dye sensitized solar cells applications

One dimensional (1-D) CdS nanowires have been grown through a low temperature chemical route and have been sensitized with eosin-G and ethyl eosin dyes to broaden the absorption spectrum of CdS and to enhance the photoelectrochemical (PEC) performance under illumination. The used method is advantageous due to its simplicity, low cost, scalability, and controllability. Interestingly, eosin-G and ethyl eosin dyes yield nearly four- and six-fold increase in device efficiency compared to bare CdS when tested in dye-sensitized solar cell assembly. Structural, surface morphological, optical, and surface wettability studies have been formulated for CdS, whereas identification of materials along with PEC investigations were conducted through current density–voltage (J-V), external quantum efficiency (EQE), characteristics under the illumination of 94.6 mW/cm² (AM 1.5G), and electrochemical impedance spectroscopy (EIS).     

有机薄膜太阳能电池发展探究

本文介绍了有机薄膜太阳能电池的概况、分类及发展趋势,阐述了利用有机、无机材料去制备有机/无机复合材料并应用于有机薄膜太阳能电池的必要性,最后介绍了非晶硅太阳电池的应用市场。     

Supramolecular Approaches to Nanoscale Morphological Control in Organic Solar Cells

Having recently surpassed 10% efficiency, solar cells based on organic molecules are poised to become a viable low-cost clean energy source with the added advantages of mechanical flexibility and light weight. The best-performing organic solar cells rely on a nanostructured active layer morphology consisting of a complex organization of electron donating and electron accepting molecules. Although much progress has been made in designing new donor and acceptor molecules, rational control over active layer morphology remains a central challenge. Long-term device stability is another important consideration that needs to be addressed. This review highlights supramolecular strategies for generating highly stable nanostructured organic photovoltaic active materials by design.     

Recent advances in conjugated polymers for light emitting devices

A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review.     

Charge-Transfer Complexes of Conjugated Polymers

Donor acceptor blends of conjugated polymers (CPs) are workhorse materials for the state-of-the-art polymer solar cells. Although earlier it was suggested that charge transfer in these blends occurred only in the excited electronic state, a body of evidence for ground-state charge transfer and the corresponding charge-transfer complex (CTC) formation has been reported in the last decade. In some CP:acceptor blends, the CTC is pronounced and can be noticed visually as a colour change, while in more common CP:fullerene blends it is very weak. However, in both, the CTC governs charge separation, which is the key photophysical process for organic solar cells, through so-called charge-transfer states. Moreover, the pronounced CTC can substantially modify the blend properties: extend the blend absorption in the red and infrared regions, change the morphology to facilitate donor acceptor intermixing, stimulate polymer self-organization and ordering, and increase the polymer photooxidation stability. Addition of one of the strongest organic acceptors, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄-TCNQ), to the CP:fullerene blend is an example of organic doping (a CTC with full charge transfer), improving the blend structural and electronic properties and finally the solar cell performance. In this review, we summarize the current knowledge on CTCs in various CP:acceptor blends and the impact of CTC on the blend properties and the device performance.     

芴液晶的研究进展

介绍了近年来芴液晶的研究进展,包括以芴酮(醇)及9位取代芴为核心的液晶化合物,阐述了这类化合物的结构与液晶性质及光电性质之间的关系。该类化合物在光电发光材料、有机太阳能电池材料等领域有广泛的应用前景。