Plastic Solar Cells

Recent developments in conjugated‐polymer‐based photovoltaic elements are reviewed. The photophysics of such photoactive devices is based on the photo‐induced charge transfer from donor‐type semiconducting conjugated polymers to acceptor‐type conjugated polymers or acceptor molecules such as Buckminsterfullerene, C₆₀. This photo‐induced charge transfer is reversible, ultrafast (within 100 fs) with a quantum efficiency approaching unity, and the charge‐separated state is metastable (up to milliseconds at 80 K). Being similar to the first steps in natural photosynthesis, this photo‐induced electron transfer leads to a number of potentially interesting applications, which include sensitization of the photoconductivity and photovoltaic phenomena. Examples of photovoltaic architectures are presented and their potential in terrestrial solar energy conversion discussed. Recent progress in the realization of improved photovoltaic elements with 3 % power conversion efficiency is reported.     

纳米薄膜太阳能电池

介绍了纳米薄膜太阳能电池的基本原理与分类,比较了纳米薄膜太阳能电池与传统固态结太阳能电池的优劣,得出了虽然目前纳米薄膜太阳能电池转换效率还无法与传统固态结太阳能电池相比,但由于其制造成本低廉、工艺简单、光子吸收效率高等潜在优势,极具应用前景的结论。     

Solar Cells: Performance Optimization of Polymer Solar Cells Using Electrostatically Sprayed Photoactive Layers (Adv. Funct. Mater. 20/2010)

Polymer solar cells (PSCs) are fabricated using a novel film deposition method, the electrostatic spray (e‐spray) technique. Stable atomization and uniform deposition of the polymer blend by e‐spray are achieved by manipulating the solution concentration, the solvent composition, and the electric field. The performance of PSCs is primarily influenced by the inherent film morphology of the e‐sprayed polymer‐blend active layers, which is significantly different from that of the conventional films that are formed using the spin‐coating (SC) method. The intrinsically formed interfacial boundaries between the e‐sprayed blend pancakes resist charge transport, which unfavorably influences device efficiency. The internal series resistance (R_S) of the PSCs that are formed using the e‐spray method (e‐spray‐PSC) is significantly reduced by a solvent vapor soaking (SVS) treatment in addition to the conventional thermodynamic nanomorphology controls. The detailed relationship between the morphologies (film morphology and internal nanomorphology) and the R_S is revealed using impedance spectroscopy. The performance of the e‐spray‐PSCs is comparable to those of the PSCs that are fabricated using the SC method under identical conditions. Therefore, the e‐spray method can be used to fabricate ultralow‐cost PSCs, because of the performance results combined with the intrinsic advantages that the e‐spray method is simple and has a low materials loss.     

微晶硅NIP太阳电池

微晶硅NIP太阳电池具有许多优点,如用于制备柔性太阳电池可极大地扩展太阳电池的应用空间,保护窗口层免受等离子轰击以保持其性能,以及扩大窗口层的光学带隙提高太阳电池的开路电压和短路电流等.综合介绍了微晶硅NIP太阳电池的基本原理、研究现状、存在的问题并展望其发展前景.     

电化学清洗在太阳能电池制绒前的应用

在太阳能电池制造工业中,为解决硅片制绒前的传统表面处理存在的药剂消耗多以及硅片去除量大的问题,引入电化学清洗的方法。这种方法是利用专用试剂电解后的强氧化性质,通过腐蚀、氧化与清洗的结合,有效清洗硅片表面有机物,且硅片去除量小。从实验中可以看出,去除量减少了1/2。通过应用金刚石膜电极,可高效生产专用试剂电解液。通过XPS显示,电化学清洗能够有效去除有机物污染。对比了电化学清洗与RCA清洗后硅片制绒的效果,证明电化学清洗的制绒效果良好。使用后的电解液经过电极处理后,仍能有效重复使用,说明电化学清洗可有力地控制排放,是大型工业生产中有效去除有机物的方法。     

高效太阳能电池

设计了一种可提高太阳能电池吸收太阳光的效率和有效存储能量的方法和装置.介绍了太阳能电池的伏安特性和法拉电容的充放电特性.该装置通过凹面镜实现太阳光的双面吸收,并以法拉电容存储太阳能.和传统单面受光电池以及用蓄电池储电相比,该装置太阳光吸收效率高、法拉电容充电时间快、放电电流大,可广泛适用于路灯及楼道灯照明等领域.     

From Groundwork to Efficient Solar Cells: On the Importance of the Substrate Material in Co-Evaporated Perovskite Solar Cells

Vacuum-based deposition of optoelectronic thin films has a long-standing history. However, in the field of perovskite-based photovoltaics, these techniques are still not as advanced as their solution-based counterparts. Although high-efficiency vacuum-based perovskite solar cells reaching power conversion efficiencies (PCEs) above 20% are reported, the number of studies on the underlying physical and chemical mechanism of the co-evaporation of lead iodide and methylammonium iodide is low. In this study, the impact of one of the most crucial process parameters in vacuum processes—the substrate material—is studied. It is shown that not only the morphology of the co-evaporated perovskite thin films is significantly influenced by the surface polarity of the substrate material, but also the incorporation of the organic compound into the perovskite framework. Based on these studies, a selection guide for suitable substrate materials for efficient co-evaporated perovskite thin films is derived. This selection guide points out that the organic vacuum-processable hole transport material 2,2″,7,7″-tetra(N,N-di-p-tolyl)amino-9,9-spirobifluorene is an ideal candidate for the fabrication of efficient all-evaporated perovskite solar cells, demonstrating PCEs above 19%. Furthermore, building on the insights into the formation of the perovskite thin films on different substrate materials, a basic crystallization model for co-evaporated perovskite thin films is suggested.     

第二讲:太阳电池

2.1太阳电池的基本发电原理光伏发电系统中成本最高的部分当数太阳电池,也称为光伏电池。它是光伏发电系统中科技含量最高的部分,是光伏发电系统的核心,也是目前光伏发电系统普及和发展的瓶颈。太阳电池本体研究主要集中在物理学、材料学和微电子学等领域。     

Imaging the Electric Potential within Organic Solar Cells

The charge transport in organic solar cells is investigated by surface potential measurements via scanning Kelvin probe microscopy. Access to the solar cell's cross‐section is gained by milling holes with a focused ion beam which enables the direct scan along the charge transport path. In a study of poly(3‐hexylthiophene):1‐(3‐methoxycarbonyl)propyl‐1‐phenyl[6,6]C61 (P3HT:PCBM) bulk heterojunction solar cells, the open circuit voltage is built up at the top contact. A comparison of the potential distribution within normal and inverted solar cells under operation exhibits strongly different behaviors, which can be assigned to a difference in interface properties.     

带有本征薄层的异质结太阳能电池

带有本征薄层的异质结(HIT)太阳能电池制备工艺温度低、转换效率高、高温特性好,是低价高效电池的一种。根据相关文献,遵循HIT电池发展的过程,从原理、结构、制备工艺等角度对其进行了深入分析,指出PECVD技术在制备HIT电池中存在的问题,并对HWCVD法制备高效HIT电池的前景进行了探讨,同时分析了a-Si:H/Si界面钝化、双面异质结结构、表面织构及栅线的优化设计等技术手段对制备高效HIT电池的重要性。     

太阳能电池的基本特性

能源危机与环境污染是人类正面临的重大挑战,开发新能源和可再生清洁能源是21世纪最具决定影响的技术领域之一。太阳能是一种取之不尽、用之不竭的可再生清洁能源,对太阳能电池的研究与开发也变得日益重要。从太阳能电池的结构、工作原理出发,系统地论述了表征太阳能电池特性的短路电流、开路电压和填充因子等参数以及外界条件对他们的影响。     

中间带太阳电池进展

中间带太阳电池是第三代光伏发电研究中很热门的研究领域之一。论述了中间带太阳电池的原理,以及实现中间带材料的三种方法,即量子点中间带电池、杂质带电池、高失配合金。量子点中间带太阳电池的红外吸收测量证实中间带太阳电池的基本原理是正确的。介绍了为提高短路电流,采用应力补偿技术,增加量子点层数,增大量子点的吸收系数。目前量子点中间带太阳电池的效率达到18%。阐述了杂质带的机理,研究表明,当Si中掺Ti浓度超过Mott相变浓度时,杂质抑制非辐射复合,有效载流子寿命增加。高失配合金具有不寻常的能带结构,AlGaN材料的带隙接近中间带的理想值,很可能成为下一个研究的热点。     

微晶硅太阳电池

采用VHF-PECVD技术制备了系列微晶硅太阳电池．综合测试结果表明：硅烷浓度、热阱温度和前电极都对微晶硅太阳电池的性能有影响．在湿法腐蚀的ZnO衬底上制备的电池的效率比在ZnO/SnO2复合膜上制备的电池的效率高1.5%．在优化了沉积条件后,制备出效率达6.7%的微晶硅太阳电池（Jsc=18.8mA/cm2,Voc=0.526V,FF=0.68）,电池的结构是glass/ZnO/p(μc-Si∶H)/i(μc-Si∶H)/(a-Si∶H)/Al,没有ZnO背反射电极．     

Stability of Amorphous Silicon Solar Cells

The present situation on the stability of amorphous silicon solar cells is discussed. Impurity diffusion is not expected to be a problem in normal cell operation. Interface contamination degrades Schottky barrier or MIS cells that are exposed to water vapor, but has no influence on p-i-n or n-i-p cells. Optically induced changes in the amorphous silicon have an influence, depending on cell structure and preparation conditions. Preliminary results on ? 5% efficiency n-i-p cells suggest that the efficiency will degrade by only 20% in 20 years of sunlight.     

薄膜太阳电池研究综述

薄膜太阳电池是最具发展潜力的新型能源之一,对缓解能源危机、保护人类生存环境提供了一种新的切实可行的方法。综述了目前国际上研究较多的几种薄膜太阳电池的最新进展,包括硅基薄膜(非晶硅、多晶硅)、多元化合物类(碲化镉、铜铟硒、铜铟镓硒、铜锌锡硫等)、有机薄膜太阳电池以及染料敏化太阳电池等。分析并总结了其在成本、转换效率等方面的优劣。为更有效地降低成本及提高电池效率,新技术、新结构的不断创新应该是未来薄膜太阳电池的发展趋势。