Default Latest Most Read Please wait a minute... Review Chemical Stability Issue and Its Research Process of Perovskite Solar Cells with High Efficiency Guo Xudong, Niu Guangda, Wang Liduo Acta Chim. Sinica 2015, 73 (3): 211-218. DOI: 10.6023/A14100687 Published: 23 December 2014 Abstract (2611) PDF (2186KB)(28578) Knowledge map Perovskite solar cells have recently achieved photo-electric conversion efficiency over 19% showing a promising future for a cost-competitive potovoltaic technology. However, the study of perovskite solar cells' stability didn't catch up with the step of efficiency's process, which is the key issue for commercial application of perovskite solar cells. This review discussed the basic issues of the perovskite solar cells' stability under different circumstances, such as oxygen and moisture, UV light, solution process (solvents, solutes, additives), and temperature etc. and summarized how to control the perovskite solar cells' stability under the conditions above. The purpose is to provide a better understanding about perovskite solar cells'stability and the methods to increase the stability of perovskite solar cells under different circumstances. Reference | Related Articles | Metrics Cited: Baidu(10) CSCD(10) Article Effect of Mesoporous TiO2 Layer Thickness on the Cell Performance of Perovskite Solar Cells Zhu Lifeng, Shi Jiangjian, Li Dongmei, Meng Qingbo Acta Chim. Sinica 2015, 73 (3): 261-266. DOI: 10.6023/A14110823 Published: 11 February 2015 Abstract (1599) PDF (2589KB)(2746) Knowledge map Perovskite solar cells attract great attention due to its rapidly increasing efficiency. Conventional structure of perovskite solar cell contains FTO glass substrate, compact TiO2 layer, mesoporous TiO2/CH3NH3PbI3 layer, hole transporting material layer and Au counter electrode. In this work, we fabricated perovskite solar cells with the above conventional structure. The mesoporous TiO2 layer thickness are 500, 350, 150 and 100 nm. Thickness of CH3NH3PbI3 capping layer is about 300 nm. The perovskite films and solar cells were characterized by SEM, XRD, UV-Vis absorption spectrum, photocurrent-photovoltage characteristics and electrochemical impedance spectra. XRD patterns of the perovskite films are similar, indicating the complete transfer from PbI2 to CH3NH3PbI3. Statistical results of short-circuit current, open-circuit voltage, fill factor and power conversion efficiency are compared, revealing that as mesoporous TiO2 layer thickness increasing, both photovoltage and fill factor decrease whereas short-circuit current slightly increases. Solar cells with thinner mesoporous TiO2 layer can give higher efficiency. Besides, the devices with 100 and 150 nm mesoporous TiO2 layers can present the average efficiency of 15%. The decrement of efficiency is supposed to be caused by stronger carrier recombination. Electrochemical impedance spectra and current-voltage characteristics under dark condition were applied to characterize the carrier recombination process. Nyquist plots demonstrated an increment of the recombination as the mesoporous TiO2 layer thickness increases. Charge transfer resistances were obtained by fitting Nyquist plots. The charge transfer resistances of solar cells with 100 and 350 nm mesoporous TiO2 layer decrease with bias voltage exponentially in similar slope, indicating that this change of recombination do not influence the diode quality factor. Reverse saturated current density was obtained by fitting dark current-voltage curves. The reverse saturated current densities have positive correction with mesoporous TiO2 layer thickness. As a conclusion, the change of the recombination is caused by reverse saturated current density rather than diode quality factor. Further investigation revealed that the devices with thinner mesoporous TiO2 layers exhibit relatively stronger hysteresis behavior. 15.56% of certified efficiency has been obtained for the perovskite solar cell with 150 nm-thickness mesoporous TiO2 layer. Reference | Related Articles | Metrics Review Perovskite Solar Cells: Device Construction and I-V Hysteresis Zhang Ye, Yao Zhibo, Lin Shiwei, Li Jianbao, Lin Hong Acta Chim. Sinica 2015, 73 (3): 219-224. DOI: 10.6023/A14090678 Published: 04 February 2015 Abstract (1584) PDF (2059KB)(19169) Knowledge map Research into organic-inorganic metal halide perovskite solar cells has swiftly gained momentum since the seminal work initiated by Kojima et al. in 2009, and already has delivered impressive accredited power conversion efficiency of over 17.9% within 5 years. In much previously reported research, the I-V characteristics was found to vary to a great extent with sweeping direction, which is known as I-V hysteresis. Further investigations have identified that the I-V hysteresis is also related to scanning speed, starting voltage and light soaking. We correlate such a phenomenon to different device structures and several possible causes were analyzed herein. A reliable test to obtain valid power conversion efficiency, which is to hold the device under a maximum power voltage is recommended for future research regarding this newly emerged technology. Reference | Related Articles | Metrics Review Recent Advances in Perovskite Solar Cells: Morphology Control and Interfacial Engineering 2016 Awarded Xue Qifan, Sun Chen, Hu Zhicheng, Huang Fei, Yip Hin-Lap, Cao Yong Acta Chimica Sinica 2015, 73 (3): 179-192. DOI: 10.6023/A14090674 Published: 16 November 2014 Abstract (1582) PDF (7067KB)(3374) Knowledge map Organic-inorganic hybrid perovskite solar cells are considered as a promising new generation photovoltaic technology that can be produced with very low cost. Recent studies revealed that organometal trihalide perovskite semiconductors exhibit several desired properties for photovoltaic applications including high absorption coefficient, low exciton binding energy, long carrier-diffusion lengths and facile tunable bandgaps, enabling their efficiencies leap from less than 5% to ca. 20% in small area devices in the past 5 years. Module efficiency up to 8.7% was also demonstrated, paving the way for potential commercialization of this new photovoltaic technology. In this review article, we discussed two important factors that had been employed to improve perovskite solar cell performance including morphology control of the perovskite films through advanced processing methods and also interface engineering in both conventional-type and inverted-type device structures. We also discussed the scientific and technological challenges remained to be solved before perovskite solar cells can be considered for real applications. Reference | Related Articles | Metrics Cited: Baidu(51) CSCD(10) Review All-solid-state Mesoscopic Solar Cells: From Dye-sensitized to Perovskite Rong Yaoguang, Mei Anyi, Liu Linfeng, Li Xiong, Han Hongwei Acta Chim. Sinica 2015, 73 (3): 237-251. DOI: 10.6023/A14100702 Published: 29 January 2015 Abstract (1454) PDF (6968KB)(2991) Knowledge map As one of candidates of the next generation solar cells, mesoscopic solar cells offer a wide application prospect due to the advantages of abundant raw materials, simple fabrication process, high power conversion efficiency and so on. This review presents a brief overview on the progress of solid-state mesoscopic solar cells in new materials, new technologies and new concepts from dye-sensitized solar cells to perovskite solar cells. In 1998, Grätzel group firstly incorporated solid-state organic hole transport materials spiro-OMeTAD into dye-sensitized solar cell, and fabricated an all-solid-state dye-sensitized solar cell. Though this device only obtained an efficiency of 0.74%, all-solid-state dye-sensitized solar cells became an important direction in the field of mesoscopic solar cells. In 2012, Park group and Grätzel group employed a perovskite absorber (CH3NH3)PbI3 as the sensitizer, and spiro-OMeTAD as the hole collecting layer, developing an all-solid-state mesoscopic solar cell, which was also named perovskite solar cell, with the efficiency of up to 9.7%. Since then, mesoscopic perovskite solar cells based on perovskite materials quickly become a hot topic in the field of solar cell. Presently, the highest certificated power conversion efficiency of perovskite solar cells has reached to 20.1%. As a milestone in the development history of mesoscopic solar cells, perovskite solar cells still have many challenges in material developing, interface engineering, and device stability, and are expecting new breakthroughs in the future. Reference | Related Articles | Metrics Cited: Baidu(3) CSCD(14) Perspective Solution-Processed Organic-Inorganic Hybrid Perovskites: A Class of Dream Materials Beyond Photovoltaic Applications Wang Nana, Si Junjie, Jin Yizheng, Wang Jianpu, Huang Wei Acta Chim. Sinica 2015, 73 (3): 171-178. DOI: 10.6023/A14100711 Published: 08 December 2014 Abstract (1188) PDF (2586KB)(2229) Knowledge map Organic-inorganic hybrid perovskite is a class of direct-bandgap semiconductors that can be processed as thin films from solutions by low-temperature methods. Among various solution-processable semiconductor materials, the hybrid perovskites exhibit unique combination of low bulk-trap densities, remarkable ambipolar transport properties, good broadband absorption characteristics and long charge carrier diffusion lengths, making them ideal for photovoltaic applications. Furthermore, as direct bandgap semiconductors with low bulk trap densities, the hybrid perovskite films possess remarkable luminescent properties. The bandgap of the hybrid perovskites can be tuned by crystal engineering, i.e. tuning the composition at molecular levels. These intriguing properties indicate that the hybrid perovskites may also find applications in light-emitting diodes and lasing. This paper reviews the unique properties and current research progresses of this class of dream material and provides our perspective of future directions. Reference | Related Articles | Metrics Cited: Baidu(9) Review Recent Progress of Lead Halide Perovskite Sensitized Solar Cells Zhang Taiyang, Zhao Yixin Acta Chim. Sinica 2015, 73 (3): 202-210. DOI: 10.6023/A14090656 Published: 06 November 2014 Abstract (1096) PDF (2164KB)(2664) Knowledge map Low cost organic and inorganic hybrid perovskites such as CH3NH3PbI3 has demonstrated a rapid increase in efficiency and has attracted tremendous research effort within a few years. The perovskite solar cells has evolved from traditional sensitized solar cell using liquid iodine electrolyte to solid state solar cell with either mesoporous or planar structure. The morphology controllable solution chemistry deposition of perovskite has progress into 15%~17% efficiency perovoskite solar cells reported by several groups. The perovskite sensitized solar cells has also progress from pure mesoporous structure into meso-planar hybrid one, which has the advantages of high efficiency and better stability. Here we review recent progress on the development of perovskite sensitized solar cells, different band gap perovskites and their deposition, different backbone nanostructures and their charge transfer properties. Reference | Related Articles | Metrics Cited: Baidu(15) CSCD(4) Communication Ternary Blend Organic Solar Cells Based on P3HT/TT-TTPA/PC61BM Cheng Pei, Shi Qinqin, Zhan Xiaowei Acta Chim. Sinica 2015, 73 (3): 252-256. DOI: 10.6023/A14080607 Published: 06 September 2014 Abstract (950) PDF (1403KB)(1532) Knowledge map Organic solar cells (OSCs) are a promising cost-effective alternative for utility of solar energy, and possess advantages such as low cost, light weight and flexibility. Much attention has been focused on the development of OSCs (synthesis of new donor or acceptor materials, control of morphology of active layer and fabrication of new device structures) which have seen a dramatic rise in efficiency over the last decade. Since the bulk heterojunction concept was reported in 1995, two-component (binary) blend has been predominant as active layer and achieved great success with power conversion efficiencies (PCEs) up to ca. 10%. Ternary blend of active layer consisting of a donor material, an acceptor material and a third component has received increasing attention in recent five years. The third components include light-absorbing polymers or small molecules, fullerene or non-fullerene acceptors, inorganic nanomaterials (quantum dots, metal nanomaterials or carbon-based nanomaterials) and organic nonvolatile additives (polymers or small molecules). Compared with binary blend, ternary blend may present some advantages: broader and stronger absorption; more efficient charge transfer and charge transport, better morphology and improved stability. In this work, we fabricated ternary blend OSCs based on P3HT/TT-TTPA/PC61BM blend. TT-TTPA is a conjugated small molecule with thiazolothiazole as acceptor unit, triphenylamine as donor unit and thiophene as bridge. TT-TTPA has good miscibility with PC61BM and the phase separation scale of TT-TTPA/PC61BM blend is very small. During solvent annealing and thermal annealing, the small amount of TT-TTPA in P3HT domains can move from P3HT domains to PC61BM domains, thus increase the phase purity of P3HT domains that can undergo crystallization. After optimization of the weight ratio of TT-TTPA in ternary blend, we achieved better PCE (4.41%) relative to binary blend (3.85%). Effects of TT-TTPA on absorption, crystallinity and morphology of P3HT:PC61BM blend films were investigated by UV-vis, X-ray diffraction and atomic force microscopy. Reference | Supporting Info. | Related Articles | Metrics Review Research Progress on Inorganic Buffer Layer Materials in Organic-Inorganic Hybrid Solar Cells Ye Senyun, Liu Zhiwei, Bian Zuqiang, Huang Chunhui Acta Chim. Sinica 2015, 73 (3): 193-201. DOI: 10.6023/A14100703 Published: 23 December 2014 Abstract (931) PDF (1699KB)(8887) Knowledge map Organic-Inorganic hybrid solar cells combine the advantages of organic and inorganic semiconductors, and possess promising application prospect. Although the active layer in hybrid solar cells is the most important, the electrode buffer layers, including cathode buffer layer and anode buffer layer, have a great influence on the power conversion efficiency (PCE) of the cells. Inorganic semiconductors are often used as the electrode buffer layers because of their high chemical stability, high carrier mobility, and high transparency. TiO2 and ZnO are the most widely used inorganic electron transport layer materials while inorganic hole transport layer materials, such as CuI, CuSCN and NiO, have been applied frequently in organic-inorganic hybrid solar cells. Here, we briefly review the progress on inorganic buffer layer materials in hybrid solar cells. Reference | Related Articles | Metrics Cited: Baidu(1) CSCD(3) Article Influence of Structure and Morphology of Perovskite Films on the Performance of Perovskite Solar Cells Shao Zhipeng, Pan Xu, Zhang Xuhui, Ye Jiajiu, Zhu Liangzheng, Li Yi, Ma Yanmei, Huang Yang, Zhu Jun, Hu Linhua, Kong Fantai, Dai Songyuan Acta Chim. Sinica 2015, 73 (3): 267-271. DOI: 10.6023/A14100721 Published: 25 December 2014 Abstract (914) PDF (1046KB)(1564) Knowledge map Perovskite solar cells based on the inorganic/organic hybrid perovskite have attracted increasing attention over the past 3 years. Many studies have been done in this area. Controling the morphology of the perovskite film is an effective way to improve the photoelectric conversion efficiency of the devices. In our reserch, we studied the influence of structure and morphology of perovskite films on the performance of the organic-inorganic hybrid perovskite solar cells which prepared by a sequential deposition method. Mesoporous TiO2 scaffold were introduced as electron collecting layer. Lead iodide (PbI2) was then spin cast on the TiO2 scaffold. The PbI2 subsequently transformed into the perovskite (CH3NH3PbI3) by dipping the TiO2/PbI2 film into a solution of CH3NH3I. We studied the difference between the PbI2 film with or without drying under room temperature after spin-coating. Through drying under room temperature, larger pores formed in the PbI2 film. While without drying under room temperature, smaller and shallower pores formed in the PbI2 film. The results show that larger pores in PbI2 film leads to more complete transformation of PbI2 to CH3NH3PbI3 and larger CH3NH3PbI3 particles. CH3NH3PbI3 films were prepared with three different processes: (a) direct dipping the PbI2 film with smaller pores into the CH3NH3I solution; (b) direct dipping the PbI2 with larger pores into the CH3NH3I solution; (c) dipping the PbI2 with larger pores into the CH3NH3I solution after pre-wetting.The resulting CH3NH3PbI3 films were studied with SEM, UV-vis absorption spectrum and XRD. The particles size of the CH3NH3PbI3 are 150, 250 and 350 nm for process (a), (b) and (c) respectively. CH3NH3PbI3 films fabricated through process (a) show insufficient absorption due to the insufficient transformation of the PbI2. The pre-wetting procedure leads to slower reaction result in larger CH3NH3PbI3 particle size. Devices with proper size of CH3NH3PbI3 particles show the highest photoelectric conversion efficiency. An efficiency of 13.5% was achieved with a Jsc of 17.8 mA/cm2, a Voc of 1.05 V and a FF of 72.5%. Reference | Related Articles | Metrics Cited: Baidu(7) CSCD(5) Review Silicon-based Organic/inorganic Hybrid Solar Cells Liu Ruiyuan, Sun Baoquan Acta Chim. Sinica 2015, 73 (3): 225-236. DOI: 10.6023/A14100693 Published: 02 February 2015 Abstract (769) PDF (3529KB)(1590) Knowledge map Organic-inorganic hybrid solar cells display potential to be high efficiency and low cost photovoltaics due to combined advantages of high stability, high mobility and well developed fabrication process from inorganic materials and the properties to adjust organic molecule structure, absorption spectrum and bandgap from solution processable organics. Heterojunction photovoltaics formed by silicon and organics at low temperature has drawn great interests over past five years and the reported highest power conversion efficiency (PCE) has achieved up to 13.8%. The emerging of nanotechnology allows for silicon micro/nano structures including silicon nanowires, pyramids and nanocones with excellent light absorption properties which can greatly reduce the consumption of silicon materials as well as the purity dependence. The micro/nano structures also exhibit the advantages to offer larger junction area and more effective separation pathways for charge carriers. It is noticeable that silicon nanowire-based flexible hybrid solar cells with tens of micrometers silicon substrate thickness have achieved the PCE of above 12% adopting the most popular commercialized conjugated polymer poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). With the rapid developments of new organic materials and interface engineering methods, different kinds of organic-silicon hybrid solar cells has been reported and shown superior photovoltaic characteristics. The adopted organics include PEDOT:PSS, poly(3-hexylthiophene) (P3HT), 2,2',7,7'-Tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD), poly(3-octylthiophene) (P3OT), fullerene derivative and so on. This paper reviews the device structures of silicon-based hybrid solar cells, working mechanism and related organic molecular. The hybrid heterojunction with different materials and fabrication processes has been discussed. The last section summarizes the method used to improve the performance of the hybrid solar cells and depicts the challenges and prospects of the silicon-based hybrid solar cells in the near future. Reference | Related Articles | Metrics Cited: Baidu(1) CSCD(2) Article A Novel Organic Disulfide/Thiolate Redox Mediator for Iodine-free Dye-sensitized Solar Cells Ma Yingzhuang, Zheng Lingling, Zhang Lipei, Chen Zhijian, Wang Shufeng, Qu Bo, Xiao Lixin, Gong Qihuang Acta Chim. Sinica 2015, 73 (3): 257-260. DOI: 10.6023/A14090659 Published: 21 November 2014 Abstract (739) PDF (615KB)(925) Knowledge map Over the last 20 years, much attention has been paid to renewable energy technology. Photovoltaic is a promising alternative to conventional fossil fuels. Dye-sensitized solar cells (DSCs) attract notable interest, not only due to their high efficiency and environmentally friendly nature, but also their easy fabrication and relatively low manufacture costs. Despite the high efficiencies, iodine/triiodine electrolytes have some disadvantages, such as the corrosion of the metallic electrodes and the sealing materials. It also absorbs visible light around 430 nm. Therefore, it is important to exploit the iodine-free redox couple in DSCs. An organic disulfide material of 2,5-dimercapto-1,3,4-thiadiazole (DMcT) is proved here to reduce and oxidize independently via homopolymerization and depolymerization. DMcT has been applied as cathode active material for lithium rechargeable batteries. Meanwhile, the self-redox property could be used as redox mediator in lieu of iodine/triiodine electrolytes. DMcT can be oxidized by self-polymerizing into PDMcT, which can be reduced by depolymerizing back to DMcT. In contrast to the conventional redox couples consisted of two different materials, DMcT can independently act as the redox mediator, which is the main difference between DMcT and the redox couples reported previously. Dye-sensitized solar cells consist of mesoporous TiO2, N719 dye, and this novel electrolyte achieved power conversion efficiency of 1.6% under 100 mW·cm-2 simulated sunlight (AM 1.5G) and a higher efficiency of 2.6% at weak illumination (13 mW·cm-2), implying its promising application prospect. Although the conversion efficiency is relatively low to the iodine/triiodine-based DSCs, this novel single self-redox mediator provides a new promising way to the iodine-free dye-sensitized solar cells. Reference | Supporting Info. | Related Articles | Metrics Cited: CSCD(4) Article Synthesis and Characterization of Orange 3 Derivatives as Photoelectric Materials Yang Rui, Cai Xuediao, Ding Liming Acta Chim. Sinica 2015, 73 (3): 281-288. DOI: 10.6023/A14110781 Published: 26 January 2015 Abstract (634) PDF (1348KB)(1047) Knowledge map Due to poorly solubility of the fused ring compound 4,10-dibromoanthanthrone (VAT Orange 3) in common organic solvents, its application as optoelectronic material was hindered. Here, the soluble compound 4,10-bis(4-hexyl-2-thienyl)- 6,12-bis(dicyanovinylene)dihydroanthanthrene (TCVA) was successfully synthesized by introducing alkyl-thiophenyl and cyano groups into VAT Orange 3 compound by Still coupling and Knoevenagel reaction. The properties of TCVA were investigated. The UV-vis spectrum indicated that TCVA showed strong absorbance in the solar spectrum. The TCVA exhibited lower LUMO energy level (-4.42 eV), which was comparable with fullerene acceptor material PCBM (-4.2 eV). The solar cell device ITO/ZnO/P3HT:TCVA/MoO3/Ag based on TCVA as acceptor and P3HT as donor material was fabricated. The power conversion efficiency (PCE) of 0.3% was achieved for acceptor TCVA with open-circuit voltage (Voc) of 0.22 V, short circuit current (Jsc) of 3.61 mA·cm-2 and fill factor (FF) of 37%. The solar cell based on TCVA achieved lower efficiency, maybe due to the lower LUMO energy level of TCVA and small difference of energy level (0.75 eV) between P3HT HOMO and TCVA LUMO. A lower LUMO energy level may lead to a lower open circuit voltage (Voc), since Voc is proportional to the energy level difference between the donor HOMO and acceptor LUMO. The donor polymer ploy[4,10-bis(4-hexyl-5-bromine-2-thienyl)-6,12-bis(dicyanovinylene)dihydroanthanthrene]-alt-2,6-bis(trimethyltin)-4,4-bis(2-ethylhexyl) two-thieno[3,2-b:2',3'-d]silole (PTCVADTS) with TCVA as the acceptor unit were synthesized and characterized. The polymer PTCVADTS showed good light-absorption properties, thermal stability, deep HOMO level (-5.33 eV), and low band gap (0.94 eV). Solar cell device ITO/PEDOT:PSS/ PTCVADTS:PC61BM/Ca/Al based on PTCVADTS as donor achieved an open-circuit voltage of 0.31 V and PCE of 0.018%. Compared with the LUMO level of acceptor (-4.2 eV), the lower LUMO level of donor (-4.39 eV) hindered the electron transport from donor to acceptor, which resulted in lower efficiency. Vat Orange 3 with large flat structure can expand conjugated system, which broadens the absorption. Further reducing the number of cyano group or introducing of other weaker electron withdrawing group may get results applauded. Reference | Related Articles | Metrics Cited: CSCD(1) Article Synthesis and Photovoltaic Performance of (Octyloxyphenyl)pyrido-[3,4-b]pyrazine-based Sensitizers for Dye-sensitized Solar Cells Zhang Xiaoyu, Ying Weijiang, Wu Wenjun, Li Jing, Hua Jianli Acta Chim. Sinica 2015, 73 (3): 272-280. DOI: 10.6023/A14090642 Published: 03 November 2014 Abstract (591) PDF (630KB)(1137) Knowledge map Dye-sensitized solar cell (DSSC) is one of the promising technologies for the alternative to traditional silicon- based solar cells due to its ecological and economical fabrication processes. As one of the key components of a DSSC, the sensitizers have been demonstrated to be extremely important in determining the photoelectric conversion efficiency and device stability of DSSCs. In our previous study, a series of new pyrido[3,4-b]pyrazine-based organic sensitizers (PP-I and APP-I~IV) containing different donors and π-bridges have been synthesized and employed successfully in DSSCs. However, despite their remarkable stability, all of the devices exhibited quite low open-circuit voltages (Vocs), which is adverse to the solar-to-electric power conversion efficiency (η). Therefore, to address this, we have replaced the 2,3-bis(4-methoxyphenyl)pyrido[3,4-b]pyrazine (APP) with 2,3-bis-(4-(octyloxy)phenyl)pyrido[3,4-b]pyrazine (OPP). As a result, a series of new sensitizers (OPP-I~Ⅲ) has been designed and synthesized with triphenylamine as the electron donor, OPP as the auxiliary acceptor, thiophene, furan and benzene as the π-linker, and cyanoacrylic acid as the acceptor moiety. Their optical and electrochemical properties, device performance and charge transfer kinetics were measured and studied. Compared with APP-Ⅲ, which has the highest Voc in the previous work, the Vocs of DSSCs based on OPP-I and OPP-Ⅲ have indeed been improved. Results showed that the replacement of the methoxy group with an octyloxy group can effectively reduce the π-π aggregation of the dyes on TiO2 films. Moreover, the steric hindrance of the octyloxy group successfully suppressed charge recombination and improved the open-circuit voltage. DSSCs based on OPP-Ⅲ with benzene as the π-linker have higher Voc than that of its counterparts with thiophene and furan as the π-linker, which might be ascribed to the bigger dihedral angle between benzene and OPP unit. In the end, DSSCs based on OPP-I showed the best conversion efficiency of 6.57% (Jsc=11.70 mA·cm-2, Voc=717 mV, ff=0.78) under standard global AM 1.5 solar light condition. Reference | Supporting Info. | Related Articles | Metrics Editorial New Type Solar Cells: Persistence, Opportunity and Success Meng Qingbo Acta Chimica Sinica 2015, 73 (3): 161-162. DOI: 10.6023/A1503E001 Published: 17 March 2015 Abstract (444) PDF (537KB)(1381) Knowledge map Related Articles | Metrics