Preparation of silver-coated glass frit and its application in silicon solar cells

A simple electroless plating process was employed to prepare silver-coated glass frits for solar cells. The surface of the glass frits was modified with polyvinyl-pyrrolidone（PVP） before the electroless plating process. Infrared（IR） spectroscopy,field emission scanning electron microscopy（FESEM）, and x-ray diffraction（XRD） were used to characterize the PVP modified glass frits and investigate the mechanism of the modification process. It was found that the PVP molecules adsorbed on the glass frit surface and reduced the silver ions to the silver nanoparticles. Through epitaxial growth, these nanoparticles were uniformly deposited onto the surface of the glass frit. Silicon solar cells with this novel silver coating exhibited a photoelectric conversion efficiency increase of 0.33%. Compared with the electroless plating processes, this method provides a simple route to prepare silver-coated glass frits without introducing impurity ions.

Optical Absorption Enhancement Effects of Silver Nanodisk Arrays in the Application of Silicon Solar Cell

Surface plasmon resonance of noble metal nanoparticles leads to the optical absorption enhancement effects,which have great potential applications in solar cell.By using the general numerical method of discrete dipole approximation （DDA）,we study the absorption and scattering properties of two-dimensional square silver nanodisks （2D SSN） arrays on the single crystal silicon solar cell.Based on the effective reflective index model of the single crystal silicon solar cell,we investigate the optical enhancement absorption of light energy by varying the light incident direction,particle size,aspect ratio,and interparticle spacing of the silver nanodisks.The peak values and position of the optical extinction spectra of the 2D square arrays of noble metal nanodisks are obtained with the different array structures.

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.

Reduction Bending of Thin Crystalline Silicon Solar Cells

Reported are the results of reduction the bending of thin crystalline silicon solar cells after printing and sintering of back electrode by changing the back electrode paste and adjusting the screen printing parameters without effecting the electrical properties of the cell.Theory and experiments showed that the bending of the cell is changed with its thickness of substrate,the thinner cell,the more serious bending.The bending of the cell is decreased with the thickness decrease of the back contact paste.The substrate with the thickness of 190 μm printing with sheet aluminum paste shows a relatively lower bend compared with that of the substrate printing with ordinary aluminum paste,and the minimum bend is 0.55 mm which is reduced by 52%.

Performance of Rhodamine-Sensitized Solar Cells Fabricated with Silver Nanoparticles

A plasmonic effect of silver nanoparticles (AgNPs) in dye-sensitized solar cells (DSSCs) is studied. In this investigation, the efficiency of dye-sensitized solar cells has been remarkably increased by infusion of synthesized silver nanoparticles into the TiO2 photoanode. Rhodaminederivative RdS1 was synthesized by microwave-assisted condensation of hydrazide and 3-for-mylchromone. The synthesized silver nanoparticles were characterized with UV/Vis absorption spectroscopy and transmission electron microscopy. The interfacial charge transport phenomena of the dye-sensitized solar cell (DSSCs) are determined by electrochemical impedance spectroscopy and the corresponding efficiencies are calculated using current-voltage (I-V) curve. The solar cell photoanode with silver nanoparticles infused with RdS1 in titanium dioxide had the highest solar-to-electric power efficiency at 0.17%.

Design of advanced porous silver powder with high-sintering activity to improve silicon solar cells

Silver(Ag)paste is widely used in semiconductor metallization,especially in silicon solar cells.Ag powder is the material with the highest proportion in Ag paste.The morphology and structure of Ag powder are crucial which determine its characteristics,especially for the sintering activity.In this work,a simple method was developed to synthesize a type of microcrystalline spherical Ag particles(SP-A)with internal pores and the structural changes and sintering behavior were thoroughly studied by combining ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),in-situ heating X-ray diffraction(XRD),focused ion beam(FIB),and thermal analysis measurement.Due to the unique internal pores,the grain size of SP-A is smaller,and the coefficient of thermal expansion(CTE)is higher than that of traditional solid Ag particles.As a result,the sintering activity of SP-A is excellent,which can form a denser sintered body and form silver nanoparticles at the Ag–Si interface to improve silver silicon contact.Polycrystalline silicon solar cell built with SP-A obtained a low series resistance(Rs)and a high photoelectric conversion efficiency(PCE)of 19.26%.These fill a gap in Ag particle structure research,which is significant for the development of high-performance electronic Ag particles and efficient semiconductor devices.

Recent Progress in All-Solution-Processed Organic Solar Cells

All-solution-processed organic solar cells(OSCs)(from the bottom electrode to the top electrode)are highly attractive thanks to their low cost,lightweight and high-throughput production.However,achieving highly efficient all-solution-processed OSCs remains a significant challenge.One of the key issues is the lack of high-quality solution-processed electrode systems that can replace indium tin oxide(ITO)and vacuum-deposited metal electrodes.In this paper,we comprehensively review recent advances in all-solution-processed osCs,and classified the devices as the top electrode materials,including silver nanowires(AgNWs),conducting polymers and composite conducting materials.The correlation between electrode materials,properties of electrodes,and device performance in all-solution-processed OSCs is elucidated.In addition,the critical roles of the active layer and interface layer are also discussed.Finally,the prospects and challenges of all-solution-processed OSCs are presented.

半片PERC光伏组件中太阳电池切割面EL图像发黑的研究

与整片光伏组件相比,半片光伏组件具有更高的输出功率和更优越的可靠性,但在对此类光伏组件进行电致发光(EL)检测时发现,其频繁出现太阳电池切割面EL图像发黑的问题。首先对PERC太阳电池结构及烧结工艺原理、EL成像原理进行介绍;然后通过实验对半片PERC光伏组件中太阳电池的背场和背电极搭接处的外观、银铝接触电阻和扫描电子显微镜(SEM)下的微观结构进行分析研究,以推断太阳电池切割面EL图像发黑的原因;然后对该原因开展验证实验,并由此提出针对太阳电池背场和背电极搭接处接触效果的改善措施,从而提升光伏组件的良率。研究结果表明:1)背场和背电极搭接处重叠位置存在明显撕裂空隙是导致半片PERC光伏组件中太阳电池切割面EL图像发黑的主要原因。银、铝经过高温膨胀发生融合反应,由于反应过度导致合金化程度较高,而冷却时银、铝的热膨胀系数不同,在降温时银铝浆会出现回缩现象,导致背场和背电极搭接处重叠位置撕裂,出现缝隙空洞,从而使银铝接触效果变差,银铝接触电阻数值严重偏大,电流传输异常,最终导致半片PERC太阳电池切割面的EL图像发黑。2)通过控制PERC太阳电池烧结工艺中烧结区的烧结温度峰值,可降低其背场和背电极搭接处的银铝接触电阻,改善该位置的接触效果,从而改善半片PERC太阳电池切割面EL图像发黑的情况,最终可提升半片PERC光伏组件的良率。

Highly flexible and transparent conducting silver nanowire/ZnO composite film for organic solar cells

High efficiency and flexible inverted organic solar cells have been fabricated using solution-processed silver nanowire/zinc oxide composite transparent electrodes. The transparent electrodes showed a low sheet resistance of -13 ff）.sq-1 and high transmittance of -93% as well as superior mechanical flexibility. Power conversion efficiencies of -7.57% and -7.21% were achieved for devices fabricated on glass and plastic substrate, respectively. Moreover, the flexible devices did not show any degradation in their performance even after being folded with a radius of-480 μm.

Long-term stable silver nanowire transparent composite as bottom electrode for perovskite solar cells

As the most promising alternative to traditional indium tin oxide （ITO）, silver nanowire （AgNW） composite transparent electrodes with improved stabilities compared with that of the pristine AgNWs networks have been demonstrated in various devices. However, a stable AgNW/polymer composite as the bottom electrode for perovskite solar cells has not yet been reported. Here, a long-term stable, smooth AgNW composite with an antioxidant-modified chitosan polymer was developed. The modified polymer can effectively protect pristine AgNWs from side reactions with perovskite, whereas it does not block the carrier drift through the interface of the insulating polymer. The as-prepared AgNW/polymer composite electrode exhibited a root mean square roughness below 10 nm at a scan size of 50 μm × 50 μm, and its original sheet resistance did not change obviously after aging at 85 ℃ for 40 days in air. As a result, the perovskite solar cell employing the composite as the bottom electrode yielded a power conversion efficiency of 7.9%, which corresponds to nearly 75% of that of the reference device with an ITO electrode.

Deterioration behavior of c-Si solar cell decorated with silver nanoparticles

Silver nanoparticles(AgNPs) with well-distributed sizes were prepared by magnetron sputtering on slides and crystalline silicon(c-Si) solar cell following by annealing at different temperatures. The morphologies,optical and photovoltaic performance were investigated in detail. The spectroscopic result shows that two resonance peaks resulting from coupling effect among neighboring particles are difficult to obtain by other chemical methods.The photovoltaic performances reveal that the solar cells decorated with AgNPs significantly are degraded, including a maximal decrease of 20.4 % in short-circuit density and 53.9 % in energy conversion efficiency. The lowest efficiency achieved is 5.85 % for c-Si solar cells with AgNPs annealed at 500 ℃. The deterioration should result from the synergetic effect of the intrinsic absorption of single particle and coupling absorption between neighboring particles.

Large-area, Flexible Polymer Solar Cell Based on Silver Nanowires as Transparent Electrode by Roll-to-Roll Printing

Conventional organic solar cell＇s （OSC） architectures, including rigid transparent substrate （Glass）, conductive electrode （Indium tin oxide, ITO） and small working areas, are widely utilized in organic photovoltaic fields. However, such a structure as well as conventional spin-coating method obviously restrict their industrial application. In this article, we report the deposition of silver nanowires （AgNWs） on the flexible substrate by slot-die printing. The obtained AgNWs films exhibited a high transmittance and a low resistance, and were further used as the transparent conductive electrode ofOSCs. A typical conjugated polymer, poly[（2-5-bis（2-hexyldecyloxy）phenylene）-alt-（5,6-difluoro-4,7-di（thiophen-2-yl）benzo[c] [1,2,5]thiadiazole）] （PPDT2FBT）, was used as the active material to fabricate large-area （7 cm2） solar cells by a slot-die coating process. The power conversion efficiency （PCE） could reach 1.87% initially and further increased to 3.04% by thermal annealing. Compared to the performance of reference cell on ITO substrate, the result indicated that the AgNWs could be developed as an alternative substitute of conductive electrode to fabricate the large-area flexible OSCs by roll-to-roll printing.

Solution-Processed Silver Nanowire as Flexible Transparent Electrodes in Organic Solar Cells

Organic solar cells(OSCs)have attracted much attention due to their advantages in fabricating flexible and semi-transparent devices.Especially,the light weight,flexibility and spectral adjustability make OSCs superior to silicon,perovskite and other thin film based solar cells in applications of integrated photovoltaic devices and wearable electronics.In flexible and semi-transparent OSCs,transparent conducting electrodes(TCEs)play a key role in obtaining high performances.Among various TCEs,silver1 n anowire(AgNW)has become a promisi ng can didate due to its low sheet resistance,high optical transparency,excellent mechanical flexibility and solution processability.In this article,we review the recent advances in AgNW-based TCEs and their applications in the field of OSCs.Firstly,we introduce the general properties of AgNW including optoelectronic and mechanical characteristics.Secondly,the preparation methods of AgNW are discussed,along with some approaches on the optimization of AgNW to overcome the shortcomings of TCEs.Thirdly,we discuss the applications of AgNW as TCEs in fabricating flexible and semi-transparent OSCs,including the use of AgNW as bottom and top electrodes.Finally,we point out the challenges in AgNW-based TCEs and suggest several guidelines for preparing AgNW so as to meet the demands for the practical use of OSCs.

Applying Silver Tellurite to Optimize Ag/Si Contact Interface in Silicon Solar Cells

Nowadays,researches on developing new etching materials to optimize the Ag/Si contact interface in silicon solar cells(SSCs)are rare,which alleviates the further development of SSCs.In this study,silver tellurite(Ag2 TeO3,monoclinic,P21/a(14))is synthesized and developed as an excellent etching material in SSCs.The Ag2TeO3 displays a low starting temperature of etching Si3N4 of^545°C,which is^160°C lower than that of PbO.Besides,by applying Ag2TeO3,conductive silver nanoparticles with a length of about 300~500 nm and a thickness of^50 nm form in the Ag/Si contact interface,which effectively reduces the Ag-Si contact resistance,and leads to a high solar cell efficiency of^18.4%.This study opens a new window for further enhancing the solar cell efficiency in the future.

银粉对硅异质结太阳电池用低温银浆的影响综述

银浆是硅异质结太阳电池的重要材料,更低的体积电阻率和接触电阻、良好的附着力、优良的细线印刷性能及组件栅线抗腐蚀老化是其不断改进的方向。作为导电相,银粉的性能和含量对银浆有着至关重要的影响。该文基于低温固化银浆导电机理以及SHJ电池对银浆性能的追求,综述了银粉的振实密度、形貌、粒径、表面处理剂及其与有机物的适配。进一步探讨了纳米银粉和银包铜粉在SHJ太阳电池用低温银浆中的应用。

Improved Ag-Si interface performance for Si solar cells using a novel Te-based glass and recrystallization process of Ag

In order to prove that the Te-based glass frit could be applied to Ag pastes to fabricate Ag electrode and elucidate the reactions among Ag,the frit,and the Si wafer,the Te-based glass and Ag pastes with different contents of glass frit(0 wt%,1 wt%,3 wt%,5 wt%,and 7 wt%)were prepared.The microstructures of Ag electrodes and the phase analysis of interface between Ag electrodes and the Si wafer were investigated using scanning electron microscopy(SEM)coupled with energy-dispersive X-ray spectroscopy(EDX)and X-ray diffraction(XRD).When the content of glass frit is 3 wt%,the Ag electrode has good adhesion with Si wafer.What’s more,Ag crystallites and metallic Te could be found on the Si wafer.These results suggest that the TeO_(2) in the glass frit could react with SiNx anti-reflecting coating(ARC)and Si to serve as a medium for forming Ag crystallites.

毛细悬浮液正面银浆制备与丝网印刷助力晶硅太阳能电池降本提效

随着传统能源的不断消耗,可再生绿色能源已成为当前社会发展的主流。太阳能作为一种可再生的清洁能源,具有低成本、清洁环保等优势,被广泛应用于各领域。晶硅太阳能电池是目前可量产的高效电池,其中正面银浆是关键组成部分,直接影响电池效率。目前,通常采用丝网印刷工艺用银浆制备电极栅线。然而,银浆中含有的多种添加剂会对电池性能产生影响。利用毛细管悬浮理论对正面银浆的制备及应用进行探索,通过材料表征、流变性分析和丝网印刷,研究了毛细管悬浮液的形成及组分配比对银浆流变性能和栅线形貌的影响。粘度测试结果显示,不同比例组分对毛细悬浮液银浆的流变性和丝网印刷的电极栅线形貌有显著地影响。采用丝网印刷工艺,利用毛细悬浮液银浆制备出平均宽度为28.62μm、平均高度为10.53μm、高宽比为0.37的栅线。相比传统银浆体系,毛细悬浮液银浆中减少了添加剂的使用,烧结后杂质残留更少,电极线电阻减小,提高了太阳能电池的转换效率。电性能模拟结果显示,与传统银浆体系相比,毛细悬浮液银浆使太阳能电池的填充因子(FF)提高0.15%、光电转化效率(Eta)提高0.03%。本研究为光伏行业的提效降本提供了一种新的可行性方案。

“Reinforced concrete”-like flexible transparent electrode for organic solar cells with high efficiency and mechanical robustness

Flexible transparent electrodes(FTEs) with robust mechanical stability are crucial for the industrial application of flexible organic solar cells(OSCs). However, their production remains challenging owing to the difficulty in balancing the conductivity,transmittance, and adhesion of FTEs to substrates. Herein, we present the so-called “reinforced concrete” strategy which finetunes the structure of silver nanowires(Ag NWs)-based FTEs with polydopamine(PDA) possessing good adhesion properties and moderate reducibility. The PDA reduces Ag+to form silver nanoparticles(Ag NPs) which grow like “rivets” at the Ag NW junction sites;PDA stabilizes the Ag NW skeleton and improves the adhesion between the Ag NWs and polyethylene terephthalate(PET) substrate and interface layer. The obtained Ag NW:PDA:Ag NP FTE exhibits excellent optoelectronic properties and high mechanical stability. The resulting flexible OSCs exhibit 17.07% efficiency, high flexibility during 10,000 bending test cycles, and robust peeling stability. In addition, this “reinforced concrete”-like FTE provides great advantages for the production of large-area flexible OSCs, thereby paving a new way toward their commercial application.

Enhanced efficiency of graphene-silicon Schottky junction solar cell through inverted pyramid arrays texturation

Nanostructures of silicon are gradually becoming hot candidate due to outstanding capability for trapping light and improving conversion efficiency of solar cell. In this paper, silicon nanowires（SiNWs） and silicon inverted pyramid arrays（SiIPs） were introduced on surface of Gr-Si solar cell through silver and copper-catalyzed chemical etching, respectively. The effects of SiNWs and SiIPs on carrier lifetime, optical properties and efficiency of Gr-SiNWs and Gr-SiIPs solar cells were systematically analyzed. The results show that the inverted pyramid arrays have more excellent ability for balancing antireflectance loss and surface area enlargement. The power conversion efficiency（PCE） and carrier lifetime of Gr-SiIPs devices respectively increase by 62% and 34% by comparing with that of Gr-SiNWs solar cells. Finally, the Gr-SiIPs cell with PCE of 5.63% was successfully achieved through nitric acid doping. This work proposes a new strategy to introduce the inverted pyramid arrays for improving the performance of Gr-Si solar cells.

Single-wall carbon nanotube-containing cathode interfacial materials for high performance organic solar cells

Water/alcohol soluble cathode interfacial materials(CIMs)are playing important roles in optoelectronic devices such as organic light emitting diodes,perovskite solar cells and organic solar cells(OSCs).Herein,n-doped solution-processable single-wall carbon nanotubes(SWCNTs)-containing CIMs for OSCs are developed by dispersing SWCNTs to the typical CIMs perylene diimide(PDI)derivatives PDIN and PDINO.The Raman and X-ray photoelectron spectroscopy(XPS)measurement results illustrate the ndoped behavior of SWCNTs by PDIN/PDINO in the blend CIMs.The blended and n-doped SWCNTs can tune the work function and enhance the conductivity of the PDI-derivative/SWCNT(PDI-CNT)composite CIMs,and the composite CIMs can regulate and down-shift the work function of cathode,reduce the charge recombination,improve the charge extraction rate and enhance photovoltaic performance of the OSCs.High power conversion efficiency(PCE)of 17.1%and 17.7%are obtained for the OSCs based on PM6:Y6 and ternary PM6:Y6:PC_(71) BM respectively with the PDI-CNTcomposites CIMs.These results indicate that the ndoped SWCNT-containing composites,like other n-doped nanomaterials such as zero dimensional fullerenes and two dimensional graphenes,are excellent CIMs for OSCs and could find potential applications in other optoelectronic devices.