Photocurrent improvement of an ultra-thin silicon solar cell using the localized surface plasmonic effect of clustering nanoparticles

The cluster-shaped plasmonic nanostructures are used to manage the incident light inside an ultra-thin silicon solar cell.Here we simulate spherical,conical,pyramidal,and cylindrical nanoparticles in a form of a cluster at the rear side of a thin silicon cell,using the finite difference time domain(FDTD)method.By calculating the optical absorption and hence the photocurrent,it is shown that the clustering of nanoparticles significantly improves them.The photocurrent enhancement is the result of the plasmonic effects of clustering the nanoparticles.For comparison,first a cell with a single nanoparticle at the rear side is evaluated.Then four smaller nanoparticles are put around it to make a cluster.The photocurrents of 20.478 mA/cm2,23.186 mA/cm2,21.427 mA/cm2,and 21.243 mA/cm2 are obtained for the cells using clustering conical,spherical,pyramidal,cylindrical NPs at the backside,respectively.These values are 13.987 mA/cm2,16.901 mA/cm2,16.507 mA/cm2,17.926 mA/cm2 for the cell with one conical,spherical,pyramidal,cylindrical NPs at the backside,respectively.Therefore,clustering can significantly improve the photocurrents.Finally,the distribution of the electric field and the generation rate for the proposed structures are calculated.

Effective absorption enhancement in small molecule organic solar cells using trapezoid gratings

We demonstrate that the optical absorption is enhanced in small molecule organic solar cells by using a trapezoid grating structure. The enhanced absorption is mainly attributed to both waveguide modes and surface plasmon modes, which is simulated by using finite-difference time-domain method. The simulated results show that the surface plasmon along the semitransparent metallic Ag anode is excited by introducing the periodical trapezoid gratings, which induce the increase of high intensity field in the donor layer. Meanwhile, the waveguide modes result in a high intensity field in acceptor layer. The increase of field improves the absorption of organic solar cells significantly, which is demonstrated by simulating the electrical properties. The simulated results also show that the short-circuit current is increased by 31% in an optimized device, which is supported by the experimental measurement. Experimental result shows that the power conversion efficiency of the grating sample is increased by 7.7%.

Hot-electron emission-driven energy recycling in transparent plasmonic electrode for organic solar cells

Plasmonic metal electrodes with subwavelength nanostructures are promising for enhancing light harvesting in photovoltaics.However,the nonradiative damping of surface plasmon polaritons(SPPs)during coupling with sunlight results in the conversion of the excited hot-electrons to heat,which limits the absorption of light and generation of photocurrent.Herein,an energy recycling strategy driven by hotelectron emission for recycling the SPP energy trapped in the plasmonic electrodes is proposed.A transparent silver-based plasmonic metal electrode(A-PME)with a periodic hexagonal nanopore array is constructed,which is combined with a luminescent organic emitter for radiative recombination of the injected hot-electrons.Owing to the suppressed SPP energy loss via broadband hot-electron emission,the A-PME achieves an optimized optical transmission with an average transmittance of over 80%from 380 to 1200 nm.Moreover,the indium-tin-oxide-free organic solar cells yield an enhanced light harvestingwith a power conversion efficiency of 16.1%.

Improving the UV-light stability of silicon heterojunction solar cells through plasmon-enhanced luminescence downshifting of YVO_(4):Eu^(3+),Bi^(3+)nanophosphors decorated with Ag nanoparticles

The ultraviolet(UV)light stability of silicon heterojunction(SHJ)solar cells should be addressed before large-scale production and applications.Introducing downshifting(DS)nanophosphors on top of solar cells that can convert UV light to visible light may reduce UV-induced degradation(UVID)without sacrificing the power conversion efficiency(PCE).Herein,a novel composite DS nanomaterial composed of YVO_(4):Eu^(3+),Bi^(3+)nanoparticles(NPs)and AgNPs was synthesized and introduced onto the incident light side of industrial SHJ solar cells to achieve UV shielding.The YVO_(4):Eu^(3+),Bi^(3+)NPs and Ag NPs were synthesized via a sol-gel method and a wet chemical reduction method,respectively.Then,a composite structure of the YVO_(4):Eu^(3+),Bi^(3+)NPs decorated with Ag NPs was synthesized by an ultrasonic method.The emission intensities of the YVO_(4):Eu^(3+),Bi^(3+)nanophosphors were significantly enhanced upon decoration with an appropriate amount of~20 nm Ag NPs due to the localized surface plasmon resonance(LSPR)effect.Upon the introduction of LSPR-enhanced downshifting,the SHJ solar cells exhibited an~0.54%relative decrease in PCE degradation under UV irradiation with a cumulative dose of 45 k W h compared to their counterparts,suggesting excellent potential for application in UV-light stability enhancement of solar cells or modules.

Enhanced organic solar cell performance: Multiple surface plasmon resonance and incorporation of silver nanodisks into a grating‐structure electrode

In this study, plasmonic nanostructures were examined to enhance the light harvesting of organic thin-film solar cells (OSCs) by multiple surface plasmon resonance (SPR) phenomena originating from the grating-coupled configuration with a Blu-ray Disc recordable (BD-R)-imprinted aluminum (Al) grating structure and the incorporation of a series of silver nanodisks (Ag NDs). The devices with such a configuration maximize the light utilization inside OSCs via light absorption, light scattering, and trapping via multiple surface plasmon resonances. Different types and sizes of metallic nanoparticles (NPs), i.e., gold nanoparticles (Au NPs), Ag nanospheres (Ag NSs), and Ag NDs, were used, which were blended separately in a PEDOT:PSS hole transport layer (HTL). The device structure comprised of grating- imprinted-Al/P3HT:PCBM/Ag ND:PEDOT:PSS/ITO. Results obtained from the J–V curves revealed that the power conversion efficiency (PCE) of grating-structured Al/P3HT:PCBM/PEDOT:PSS/ITO is 3.16%;this value is ~6% higher than that of a flat substrate. On the other hand, devices with flat Al and incorporated Au NPs, Ag NSs, or Ag NDs in the HTL exhibited PCEs ranging from 3.15% to 3.37%. Furthermore, OSCs with an Al grating substrate were developed by the incorporation of the Ag ND series into the PEDOT:PSS layer. Compared with that of a reference device, the PCEs of the devices increased to 3.32%–3.59%(11%–20% improvement), indicating that the light absorption enhancement at the active layer corresponds to the grating-coupled surface plasmon resonance and localized surface plasmon resonance excitations with strong near-field distributions penetrating into the active layer leading to higher efficiencies and subsequent better current generation.

Nano Ag-enhanced photoelectric conversion efficiency in all-inorganic,hole-transporting-layer-free CsPbIBr_(2) perovskite solar cells

All-inorganic,hole-transporting-layer-free CsPbIBr_(2)perovskite solar cells have great potential for development,but their device performance needs to be further improved.Recently,metal nanostructures have been successfully applied in the field of solar cells to improve their performance.Nano Ag-enhanced power conversion efficiency(PCE)in one CsPbIBr_(2)perovskite solar cell utilizing localized surface plasmons of Ag nanoparticles(NPs)on the surface has been researched experimentally and by simulation in this paper.The localized surface plasmon resonance of Ag NPs has a near-field enhancement effect,which is expected to improve the light absorption of CsPbIBr_(2)perovskite photovoltaic devices.In addition,Ag NPs have a forward-scattering effect on the incident light,which can also improve the performance of CsPbIBr_(2)-based perovskite photovoltaic devices.By directly assembling Ag NPs(with a size of about 150 nm)on the surface of fluorine-doped tin oxide it is found when the particle surface coverage is 10%,the CsPbIBr_(2)perovskite photovoltaic device achieves a best PCE of 2.7%,which is 9.76%higher than that of the control group.Without changing any existing structure in the ready-made solar cell,this facile and efficient method has huge applications.To the best of our knowledge,this paper is the first report on nano Ag-enhanced photoelectric conversion efficiency in this kind of CsPbIBr_(2)perovskite solar cell.

The enhancement of 21.2%-power conversion efficiency in polymer photovoltaic cells by using mixed Au nanoparticles with a wide absorption spectrum of 400 nm–1000 nm

Au nanoparticles （NPs） mixed with a majority of bone-like, rod, and cube shapes and a minority of irregu- lar spheres, which can generate a wide absorption spectrum of 400 nm-1000 nm and three localized surface plas- mon resonance peaks, respectively, at 525, 575, and 775 nrn, are introduced into the hole extraction layer poly（3,4- ethylenedioxythiophene）：poly（4-styrenesulfonate） （PEDOT：PSS） to improve optical-to-electrical conversion performances in polymer photovoltaic ceils. With the doping concentration of Au NPs optimized, the cell performance is significantly improved： the short-circuit current density and power conversion efficiency of the poly（3-hexylthiophene）： [6,6]-phenyl- C60-butyric acid methyl ester cell are increased by 20.54% and 21.2%, reaching 11.15 mA.cm-2 and 4.23%. The variations of optical, electrical, and morphology with the incorporation of Au NPs in the cells are analyzed in detail, and our results demonstrate that the cell performance improvement can be attributed to a synergistic reaction, including： 1） both the local- ized surface plasmon resonanceand scattering-induced absorption enhancement of the active layer, 2） Au doping-induced hole transport/extraction ability enhancement, and 3） large interface roughness-induced efficient exciton dissociation and hole collection.

Au@Ag@SiO_(2)纳米棒等离子体对钙钛矿太阳能电池铅含量的降低策略

Pb基卤化物钙钛矿的环境毒性是阻碍钙钛矿光伏技术产业应用的重要因素。通过降低钙钛矿吸光层厚度来减少Pb的用量(即物理降铅)是降低铅基钙钛矿太阳能电池(perovskite solar cells,PSCs)环境毒性的重要方法,但吸光层厚度的降低将显著削弱电池的光捕获能力。通过调节Au@Ag@SiO_(2)纳米棒等离子体粒子的共振吸收波长与钙钛矿吸收光谱进行匹配,并将其引入TiO_(2)介孔层,利用金属等离子体粒子的局域表面等离子共振(localized surface plasmon resonance,LSPR)产生的陷光效应实现了薄吸光层PSCs对长波长可见光的强化利用。当吸光层厚度从常规720 nm大幅降低到260 nm时,薄吸光层PSCs的光电转换效率仅下降14.1%(效率从19.1%下降到16.4%),但电池的Pb用量减少了63.9%。研究表明,利用金属等离子体粒子的LSPR效应可大幅减少PSCs的铅含量并同时保持较高的光电转换效率。

超细铜纳米线的低温制备及其室内光伏电池性能的研究

金属纳米材料的局域表面等离子体共振(LSPR)具有非常独特的光电性质,对基于LSPR效应提高薄膜太阳能电池光伏性能的研究已成为国内外广泛关注的热点研究领域之一。采用低温水热还原法以葡萄糖为还原剂,二水合氯化铜为铜源,十六烷基胺和十八烷基胺为封端剂合成了直径约为20 nm的面心立方结构的超细铜纳米线。利用X射线衍射(XRD)、紫外可见吸收光谱(UV-vis)和扫描电子显微镜(SEM)对合成产物的晶体结构、形貌和光学性质进行了表征。此外,将铜纳米线和氧化锡纳米粒子(SnO 2 NPs)混合作为电子传输层,利用其LSPR效应提高钙钛矿太阳能电池(PSCs)的光捕获效率和电子输运效率,并对器件的室内光伏性能的影响进行了研究。研究表明,与未引入Cu NWs的器件相比,引入Cu NWs的PSCs在光强100 mW/cm^(2)的模拟太阳光下的能量转换效率(PCE)从原来的18.4%提升至20.5%;在2000 lux的室内LED光源下的PCE从原来的27.8%大幅提升至35.2%,室内光伏效率提升幅度高达26.6%。

Ag纳米颗粒对有机小分子太阳能电池性能的改善

在有机小分子太阳能电池CuPc/C60和TiOPc/C60的阳极ITO表面分别制备了一层Ag纳米颗粒,并采用MoO3作为阳极缓冲层,器件的性能均得到有效改善。Ag纳米颗粒的引入所形成的表面等离子激元共振可显著提高有机光活性层的吸收效率和光生激子的分解效率;而MoO3有效抑制了光生激子在有机/金属界面处发生的猝灭,提高了器件的短路电流,并保持其它性能不变,最终提高器件的光电转化效率。

基于金纳米棒@二氧化硅表面等离子体共振增强的有机太阳能电池

把包裹SiO_2的金纳米棒(AuNRs@SiO_2)掺杂到有机太阳能电池的活性层中,利用表面等离子体共振效应来增强活性层对光的吸收,从而提高有机太阳能电池的能量转换效率。研究了不同掺杂浓度和不同包裹厚度对电池性能的影响。结果表明,掺杂浓度为1. 5%时,器件性能最佳,能量转换效率达到4. 02%; SiO_2壳层厚度为3 nm时,转换效率达到4. 38%,较标准电池提升了29. 2%。

有机太阳能电池能量转化效率的提高思路

能源问题是目前最为关注的焦点之一,随着社会的进步和工业的发展,地球上已探明可使用的化学燃料能源,包括石油、天然气和煤等,日趋枯竭。太阳能的利用已引起各国的重视。光伏器件是太阳能利用的最为重要的手段之一,有机太阳电池在此类器件中将承担极其重要的角色。但低的光电转换效率是阻碍其产业化的瓶颈。为此简要综述了提高有机太阳能电池能量转化效率的两个思路,并指出了有待解决的问题。

金属纳米结构的表面等离子体激元提高有机太阳能电池光电转换效率的研究进展

介绍了应用金属纳米结构的表面等离子体激元提高有机太阳能电池效率的最新研究进展。表面等离子体激元的激发取决于纳米结构的材料、尺寸、形状、密度、和周围的电介质环境等参数。调控这些参数,可以有效利用金属纳米结构增加有机太阳能电池活性层的光吸收,同时金属纳米结构表面增强的电场可促进光激子解离为载流子。因此,应用金属纳米结构的表面等离子体激元将是进一步增加有机太阳能电池的光电转换效率的重要方案。

利用蛾眼结构提高有机太阳能电池光吸收效率的理论研究

为提高有机太阳能电池(OSCs)的能量转换效率,将蛾眼微结构应用于OSCs上。通过理论模拟计算,得出在有机层厚度一定的情况下,带有蛾眼微结构的OSCs相比于普通平板结构的OSCs的光吸收效率有较大的提高。通过对微结构形貌、周期和高度的优化,使蛾眼结构OSCs的光吸收效率比普通平板OSCs提高了11.3%。器件光场分布的模拟计算表明,光吸收效率的提高是由蛾眼结构减反增透的效果和表面等离子体(SPP)增强吸收共同导致的结果。

不同背反射结构在硅异质结太阳电池中的应用研究

该文旨在利用银纳米颗粒(Ag NPs)和SiO_(x)/Ag背反射结构提升硅异质结(SHJ)太阳电池在900~1200nm波段红外光谱响应。研究在SHJ太阳电池背光侧分别制备Ag、SiO_(x)/Ag和嵌入Ag NPs的SiO_(x)/Ag几种背反射结构,以最大限度提升SHJ太阳电池红外光谱响应。结果表明:SiO_(x)/Ag背反射结构可有效减少红外光的逃逸损失,提升太阳电池红外光谱响应,使得双面制绒SHJ太阳电池短路电流密度从37.74 mA/cm^(2)提升到38.07 mA/cm^(2);但嵌入Ag NPs并不能帮助SiO_(x)/Ag背反射结构进一步提升双面制绒SHJ电池红外光谱响应,证明了基于其局域表面等离激元共振效应仅对陷光能力较差的平面太阳SHJ电池有一定提升。

金纳米颗粒对染料敏化太阳能电池性能的优化

采用球磨法制备一系列掺杂有不同含量立方形金纳米颗粒的复合光阳极薄膜,并组装成染料敏化太阳能电池,研究立方形金纳米颗粒对光阳极薄膜以及染料敏化太阳能电池性能的影响。研究表明,当掺入立方形金纳米颗粒的质量分数为0.8%时,太阳能电池呈现出最优性能,其短路电流密度为15.32mA/cm^2,光电转换效率为6.708%,相比基于纯TiO2光阳极分别提高14.47%和12%。太阳能电池性能的显著提高主要归因于立方形金纳米颗粒独特的局域表面等离子体共振效应,其能有效改善染料分子的光吸收性能,进而提高电池的光电转换效率。

表面等离子体增强硅电池光吸收的研究进展

局域表面等离子体共振(LSPR)是光照射金属纳米粒子而引起金属内的自由电子发生集体共振使粒子周围的近场增强。将LSPR应用于太阳能电池,会使陷光效率大大增加,而同时降低表面复合损耗和电池基底的厚度要求。文章从粒子的大小、形状、阵列模式的周期及粒子周围的介电环境对太阳能电池的陷光的影响,介绍了基于LSPR性质的表面等离子体硅太阳能电池的陷光机理及其影响因素,对相应的研究做了系统的综述。

Performance optimization of dye-sensitized solar cells by gradient-ascent architecture of SiO_2@Au@TiO_2 microspheres embedded with Au nanoparticles

Highly homogeneous, well dispersed SiO_2@Au@TiO_2(SAT) microspheres decorated with Au nanoparticles(AuNPs) were prepared and incorporated into the photoanode with an optimized concentration gradientascent. The effects of SAT microspheres and the gradient-ascent architecture on the light absorption and the photoelectric conversion efficiency(PCE) of the dye-sensitized solar cells(DSSCs) were investigated.Studies indicate that the introduction of SAT microspheres and the gradient-ascent architecture in the photoanode significantly enhance the light scattering and harvesting capability of the photoanode. The DSSC with the optimized SAT gradient-ascent photoanode has the maximum short circuit current density(J_(sc)) of 17.7 mA cm^(-2) and PCE of 7.75%, remarkably higher than those of the conventional DSSC by 23.7%and 28.0%, respectively. This significantly enhancement of the performance of the DSSC can be attributed to the excellent light reflection/scattering of SAT, the localized surface plasma resonance(LSPR) effect of AuNPs within the microspheres, and the gradient-ascent architecture of SAT microspheres inside the photoanode. This study demonstrates that the tri-synergies of the scattering of SAT microspheres, the LSPR of AuNPs and the gradient-ascent architecture can effectively improve the PCE of DSSC.

表面等离子体-微腔激元对顶入射有机薄膜太阳能电池光吸收效率的增强

为了提高顶入射有机薄膜太阳能电池(TOSCs)的光吸收效率,我们将周期性矩形光栅结构引入到TOSCs中,分析了具有光栅结构的空气/Ag_1/有源层/Ag_2/空气(IMIMI)结构理想模型中复合表面等离子激元(SPPs)与微腔模式的耦合机制。通过调节光栅周期和有源层厚度,实现了复合SPPs、微腔模式以及有机材料本征吸收3个区域的重合。由于复合SPPs与微腔模式的反交叉耦合作用形成了表面等离子体-微腔激元,其局域场增强作用有效地提高了有源层的光吸收效率,提高了近19%。

等离激元共振增强多晶硅薄膜太阳电池性能研究

采用磁控溅射方法,在多晶硅薄膜太阳电池表面沉积了不同粒径大小的Au纳米粒子,利用粒径大小可调控的Au纳米粒子的局域表面等离激元共振增强效应(LSPR),对入射光中的可见光区域实现"光俘获";采用UV-vis吸收光谱对LSPR进行了研究,结果表明,LSPR能够有效拓展Au纳米粒子的光谱响应范围(400~800nm),并且,随着Au纳米粒子粒径的增大,LSPR共振吸收峰呈现出明显"红移";同时,通过SERS表征,证实LSPR能够有效增强Au纳米粒子周围的局域电磁场强度;最后,多晶硅太阳电池的J-V特性曲线表明,当Au纳米粒子溅射时间为50s时,多晶硅太阳电池光电转换效率(η)最高为14.8%,比未修饰Au纳米粒子的电池η提高了42.3%。