首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A low‐temperature solution‐processed strategy is critical for cost‐effective manufacture of flexible perovskite solar cells (PSCs). Based on an aqueous‐processed TiO2 layer, and conventional fullerene derivatives replaced by a pristine fullerene interlayer of C60, herein a facile interface engineering for making all‐solution‐processed TiO2/C60 layers in flexible n‐i‐p PSCs is reported. Due to the improvement of the perovskite grain quality, promotion of interfacial charge transfer and suppression of interfacial charge recombination, the stabilized power conversion efficiency for the flexible PSCs reaches as high as 16% with high bending resistance retention (≈80% after 1500 cycles) and high light‐soaking retention (≈100% after 100 min). In addition, the stabilized efficiency is over 19% for the rigid TiO2/C60‐based PSCs. The present work with the facile low‐temperature solution process renders the practicability for high‐performance flexible PSCs applied to wearable devices, portable equipment, and electric vehicles.  相似文献   

2.
Herein, this study reports high‐efficiency, low‐temperature ZnO based planar perovskite solar cells (PSCs) with state‐of‐the‐art performance. They are achieved via a strategy that combines dual‐functional self‐assembled monolayer (SAM) modification of ZnO electron accepting layers (EALs) with sequential deposition of perovskite active layers. The SAMs, constructed from newly synthesized molecules with high dipole moments, act both as excellent surface wetting control layers and as electric dipole layers for ZnO‐EALs. The insertion of SAMs improves the quality of PbI2 layers and final perovskite layers during sequential deposition, while charge extraction is enhanced via electric dipole effects. Leveraged by SAM modification, our low‐temperature ZnO based PSCs achieve an unprecedentedly high power conversion efficiency of 18.82% with a VOC of 1.13 V, a JSC of 21.72 mA cm?2, and a FF of 0.76. The strategy used in this study can be further developed to produce additional performance enhancements or fabrication temperature reductions.  相似文献   

3.
Polymer solar cells (PSCs) are fabricated without solvent additives using a low‐bandgap polymer, PBDTTT‐C‐T, as the donor and [6,6]‐phenyl‐C61‐butyric‐acid‐methyl‐ester (PC61BM) as the acceptor. Donor‐acceptor blend and layer‐by‐layer (LL) solution process are used to form active layers. Relative to the blend devices, the LL devices exhibit stronger absorption, better vertical phase separation, higher hole and electron mobilities, and better charge extraction at correct electrodes. As a result, after thermal annealing the LL devices exhibit an average power conversion efficiency (PCE) of 6.86%, which is much higher than that of the blend devices (4.31%). The best PCE of the LL devices is 7.13%, which is the highest reported for LL processed PSCs and among the highest reported for PC61BM‐based single‐junction PSCs.  相似文献   

4.
The high thermal stability and facile synthesis of CsPbI2Br all‐inorganic perovskite solar cells (AI‐PSCs) have attracted tremendous attention. As far as electron‐transporting layers (ETLs) are concerned, low temperature processing and reduced interfacial recombination centers through tunable energy levels determine the feasibility of the perovskite devices. Although the TiO2 is the most popular ETL used in PSCs, its processing temperature and moderate electron mobility hamper the performance and feasibility. Herein, the highly stable, low‐temperature processed MgZnO nanocrystal‐based ETLs for dynamic hot‐air processed Mn2+ incorporated CsPbI2Br AI‐PSCs are reported. By holding its regular planar “n–i–p” type device architecture, the MgZnO ETL and poly(3‐hexylthiophene‐2,5‐diyl) hole transporting layer, 15.52% power conversion efficiency (PCE) is demonstrated. The thermal‐stability analysis reveals that the conventional ZnO ETL‐based AI‐PSCs show a serious instability and poor efficiency than the Mg2+ modified MgZnO ETLs. The photovoltaic and stability analysis of this improved photovoltaic performance is attributed to the suitable wide‐bandgap, low ETL/perovskite interface recombination, and interface stability by Mg2+ doping. Interestingly, the thermal stability analysis of the unencapsulated AI‐PSCs maintains >95% of initial PCE more than 400 h at 85 °C for MgZnO ETL, revealing the suitability against thermal degradation than conventional ZnO ETL.  相似文献   

5.
The presence of non‐radiative recombination at the perovskite surface/interface limits the overall efficiency of perovskite solar cells (PSCs). Surface passivation has been demonstrated as an efficient strategy to suppress such recombination in Si cells. Here, 1‐naphthylmethylamine iodide (NMAI) is judiciously selected to passivate the surface of the perovskite film. In contrast to the popular phenylethylammonium iodide, NMAI post‐treatment primarily leaves NMAI salt on the surface of the perovskite film. The formed NMAI layer not only efficiently decreases the defect‐assisted recombination for chemical passivation, but also retards the charge accumulation of energy level mis‐alignment for vacuum level bending and prevents minority carrier recombination due to the charge‐blocking effect. Consequently, planar PSCs with high efficiency of 21.04% and improved long‐term stability (98.9% of the initial efficiency after 3240 h) are obtained. Moreover, open‐circuit voltage as high as 1.20 V is achieved at the absorption threshold of 1.61 eV, which is among the highest reported values in planar PSCs. This work provides new insights into the passivation mechanisms of organic ammonium salts and suggests future guidelines for developing improved passivation layers.  相似文献   

6.
Organic–inorganic hybrid perovskite solar cells (PSCs) are a promising photovoltaic technology that has rapidly developed in recent years. Nevertheless, a large number of ionic defects within perovskite absorber can serve as non‐radiative recombination center to limit the performance of PSCs. Here, organic donor‐π‐acceptor (D‐π‐A) molecules with different electron density distributions are employed to efficiently passivate the defects in the perovskite films. The X‐ray photoelectron spectroscopy (XPS) analysis shows that the strong electron donating N,N‐dibutylaminophenyl unit in a molecule causes an increase in the electron density of the passivation site that is a carboxylate group, resulting in better binding with the defects of under‐coordinated Pb2+ cations. Carrier lifetime in the perovskite films measured by the time‐resolved photoluminescence spectrum is also prolonged by an increase in donation ability of the D‐π‐A molecules. As a consequence, these benefits contribute to an increase of 80 mV in the open circuit voltage of the devices, enabling a maximum power conversion efficiency (PCE) of 20.43%, in comparison with PCE of 18.52% for the control device. The authors' findings provide a novel strategy for efficient defect passivation in the perovskite solar cells based on controlling the electronic configuration of passivation molecules.  相似文献   

7.
Charge transport layers play an important role in determining the power conversion efficiencies (PCEs) of perovskite solar cells (PSCs). However, it has proven challenging to produce thin and compact charge transport layers via solution processing techniques. Herein, a hot substrate deposition method capable of improving the morphology of high‐coverage hole‐transport layers (HTLs) and electron‐transport layers (ETLs) is reported. PSC devices using HTLs deposited on a hot substrate show improvement in the open‐circuit voltage (Voc) from 1.041 to 1.070 V and the PCE from 17.00% to 18.01%. The overall device performance is then further enhanced with the hot substrate deposition of ETLs as the Voc and PCE reach 1.105 V and 19.16%, respectively. The improved performance can be explained by the decreased current leakage and series resistance, which are present in PSCs with rough and discontinuous HTLs and ETLs.  相似文献   

8.
A power conversion efficiency (PCE) as high as 19.7% is achieved using a novel, low‐cost, dopant‐free hole transport material (HTM) in mixed‐ion solution‐processed perovskite solar cells (PSCs). Following a rational molecular design strategy, arylamine‐substituted copper(II) phthalocyanine (CuPc) derivatives are selected as HTMs, reaching the highest PCE ever reported for PSCs employing dopant‐free HTMs. The intrinsic thermal and chemical properties of dopant‐free CuPcs result in PSCs with a long‐term stability outperforming that of the benchmark doped 2,2′,7,7′‐Tetrakis‐(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐Spirobifluorene (Spiro‐OMeTAD)‐based devices. The combination of molecular modeling, synthesis, and full experimental characterization sheds light on the nanostructure and molecular aggregation of arylamine‐substituted CuPc compounds, providing a link between molecular structure and device properties. These results reveal the potential of engineering CuPc derivatives as dopant‐free HTMs to fabricate cost‐effective and highly efficient PSCs with long‐term stability, and pave the way to their commercial‐scale manufacturing. More generally, this case demonstrates how an integrated approach based on rational design and computational modeling can guide and anticipate the synthesis of new classes of materials to achieve specific functions in complex device structures.  相似文献   

9.
Semitransparent perovskite solar cells (st‐PSCs) have received remarkable interest in recent years because of their great potential in applications for solar window, tandem solar cells, and flexible photovoltaics. However, all reported st‐PSCs require expensive transparent conducting oxides (TCOs) or metal‐based thin films made by vacuum deposition, which is not cost effective for large‐scale fabrication: the cost of TCOs is estimated to occupy ≈75% of the manufacturing cost of PSCs. To address this critical challenge, this study reports a low‐temperature and vacuum‐free strategy for the fabrication of highly efficient TCO‐free st‐PSCs. The TCO‐free st‐PSC on glass exhibits 13.9% power conversion efficiency (PCE), and the four‐terminal tandem cell made with the st‐PSC top cell and c‐Si bottom cell shows an overall PCE of 19.2%. Due to the low processing temperature, the fabrication of flexible st‐PSCs is demonstrated on polyethylene terephthalate and polyimide, which show excellent stability under repeated bending or even crumbing.  相似文献   

10.
Despite recent breakthroughs in power conversion efficiencies (PCEs), which have resulted in PCEs exceeding 22%, perovskite solar cells (PSCs) still face serious drawbacks in terms of their printability, reliability, and stability. The most efficient PSC architecture, which is based on titanium dioxide as an electron transport layer, requires an extremely high‐temperature sintering process (≈500 °C), reveals hysterical discrepancies in the device measurement, and suffers from performance degradation under light illumination. These drawbacks hamper the practical development of PSCs fabricated via a printing process on flexible plastic substrates. Herein, an innovative method to fabricate low‐temperature‐processed, hysteresis‐free, and stable PSCs with a large area up to 1 cm2 is demonstrated using a versatile organic nanocomposite that combines an electron acceptor and a surface modifier. This nanocomposite forms an ideal, self‐organized electron transport layer (ETL) via a spontaneous vertical phase separation, which leads to hysteresis‐free, planar heterojunction PSCs with stabilized PCEs of over 18%. In addition, the organic nanocomposite concept is successfully applied to the printing process, resulting in a PCE of over 17% in PSCs with printed ETLs.  相似文献   

11.
Formamidinium (FA)‐based lead iodide perovskites have emerged as the most promising light‐absorber materials in the prevailing perovskite solar cells (PSCs). However, they suffer from the phase‐instability issue in the ambient atmosphere, which is holding back the realization of the full potential of FA‐based PSCs in the context of high efficiency and stability. Herein, the tetraethylorthosilicate hydrolysis process is integrated with the solution crystallization of FA‐based perovskites, forming a new film structure with individual perovskite grains encapsulated by amorphous silica layers that are in situ formed at the nanoscale. The silica not only protects perovskite grains from the degradation but also enhances the charge‐carrier dynamics of perovskite films. The underlying mechanism is discussed using a joint experiment‐theory approach. Through this in situ grain encapsulation method, PSCs show an efficiency close to 20% with an impressive 97% retention after 1000‐h storage under ambient conditions.  相似文献   

12.
In perovskite solar cells (PSCs), the interfaces are a weak link with respect to degradation. Electrochemical reactivity of the perovskite's halides has been reported for both molecular and polymeric hole selective layers (HSLs), and here it is shown that also NiO brings about this decomposition mechanism. Employing NiO as an HSL in p–i–n PSCs with power conversion efficiency (PCE) of 16.8%, noncapacitive hysteresis is found in the dark, which is attributable to the bias‐induced degradation of perovskite/NiO interface. The possibility of electrochemically decoupling NiO from the perovskite via the introduction of a buffer layer is explored. Employing a hybrid magnesium‐organic interlayer, the noncapacitive hysteresis is entirely suppressed and the device's electrical stability is improved. At the same time, the PCE is improved up to 18% thanks to reduced interfacial charge recombination, which enables more efficient hole collection resulting in higher Voc and FF.  相似文献   

13.
A novel wide‐bandgap electron‐donating copolymer containing an electron‐deficient, difluorobenzotriazole building block with a siloxane‐terminated side chain is developed. The resulting polymer, poly{(4,8‐bis(4,5‐dihexylthiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene‐co‐4,7‐di(thiophen‐2‐yl)‐5,6‐difluoro‐2‐(6‐(1,1,1,3,5,5,5‐heptamethyltri‐siloxan‐3‐yl)hexyl)‐2H‐benzo[d][1,2,3]triazole} (PBTA‐Si), is used to successfully fabricate high‐performance, ternary, all‐polymer solar cells (all‐PSCs) insensitive to the active layer thickness. An impressively high fill factor of ≈76% is achieved with various ternary‐blending ratios. The optimized all‐PSCs attain a power conversion efficiency (PCE) of 9.17% with an active layer thickness of 350 nm and maintain a PCE over 8% for thicknesses over 400 nm, which is the highest reported efficiency for thick all‐PSCs. These results can be attributed to efficient charge transfer, additional energy transfer, high and balanced charge transport, and weak recombination behavior in the photoactive layer. Moreover, the photoactive layers of the ternary all‐PSCs are processed in a nonhalogenated solvent, 2‐methyltetrahydrofuran, which greatly improves their compatibility with large‐scale manufacturing.  相似文献   

14.
Carbon‐based hole transport material (HTM)‐free perovskite solar cells (PSCs) have shown much promise for practical applications because of their high stability and low cost. However, the efficiencies of this kind of PSCs are still relatively low, especially for the simplest paintable carbon‐based PSCs, in comparison with the organic HTM‐based PSCs. This can be imputed to the perovskite deposition methods that are not very suitable for this kind of devices. A solvent engineering strategy based on two‐step sequential method is exploited to prepare a high‐quality perovskite layer for the paintable carbon‐based PSCs in which the solvent for CH3NH3I (MAI) solution at the second step is changed from isopropanol (IPA) to a mixed solvent of IPA/Cyclohexane (CYHEX). This mixed solvent not only accelerates the conversion of PbI2 to CH3NH3PbI3 but also suppresses the Ostwald ripening process resulting in a high‐quality perovskite layer, e.g., pure phase, even surface, and compact capping layer. The paintable carbon‐based PSCs fabricated from IPA/CYHEX solvent exhibits a considerable enhancement in photovoltaic performance and performance reproducibility in comparison with that from pure IPA, especially on fill factor (FF), owing mainly to the better contact of perovskite/carbon interface, lower trap density in perovskite, higher light absorption ability, and faster charge transport of perovskite layer. As a result, the highest power conversion efficiency (PCE) of 14.38% is obtained, which is a record value for carbon‐based HTM‐free PSCs. Furthermore, a PCE of as high as 10% is achieved for the large area device (1 cm2), also the highest of its kind.  相似文献   

15.
The development of effective and stable hole transporting materials (HTMs) is very important for achieving high‐performance planar perovskite solar cells (PSCs). Herein, copper salts (cuprous thiocyanate (CuSCN) or cuprous iodide (CuI)) doped 2,2,7,7‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9‐spirobifluorene (spiro‐OMeTAD) based on a solution processing as the HTM in PSCs is demonstrated. The incorporation of CuSCN (or CuI) realizes a p‐type doping with efficient charge transfer complex, which results in improved film conductivity and hole mobility in spiro‐OMeTAD:CuSCN (or CuI) composite films. As a result, the PCE is largely improved from 14.82% to 18.02% due to obvious enhancements in the cell parameters of short‐circuit current density and fill factor. Besides the HTM role, the composite film can suppress the film aggregation and crystallization of spiro‐OMeTAD films with reduced pinholes and voids, which slows down the perovskite decomposition by avoiding the moisture infiltration to some extent. The finding in this work provides a simple method to improve the efficiency and stability of planar perovskite solar cells.  相似文献   

16.
The room temperature (RT) processability of the photoactive layers in polymer solar cells (PSCs) from halogen‐free solvent along with their highly reproducible power conversion efficiencies (PCEs) and intrinsic thickness tolerance are extremely desirable for the large‐area roll‐to‐roll (R2R) production. However, most of the photoactive materials in PSCs require elevated processing temperatures due to their strong aggregation, which are unfavorable for the industrial R2R manufacturing of PSCs. These limiting factors for the commercialization of PSCs are alleviated by synthesizing random terpolymers with components of (2‐decyltetradecyl)thiophen‐2‐yl)naphtho[1,2‐c:5,6‐c′]bis[1,2,5]thiadiazole and bithiophene substituted with methyl thiophene‐3‐carboxylate (MTC). In contrast to the temperature‐dependent PNTz4T polymer, the resulting random terpolymers (PNTz4T‐MTC) show better solubility, slightly reduced crystallinity and aggregation, and weaker intermolecular interaction, thus enabling PNTz4T‐MTC to be processed at RT from a halogen‐free solvent. Particularly, the PNTz4T‐5MTC‐based photoactive layer exhibits an excellent PCE of 9.66%, which is among the highest reported PCEs for RT and ecofriendly halogen‐free solvent processed fullerene‐based PSCs, and a thickness tolerance with a PCE exceeding 8% from 100 to 520 nm. Finally, large‐area modules fabricated with the PNTz4T and PNTz4T‐5MTC polymer have shown 4.29% and 6.61% PCE respectively, with an area as high as 54.45 cm2 in air.  相似文献   

17.
All‐inorganic cesium lead halide (CsPbX3) perovskites have emerged as promising photovoltaic materials owing to their superior thermal stability compared to traditional organic–inorganic hybrid counterparts. However, the CsPbX3 perovskites generally need to be prepared at high‐temperature, which restricts their application in multilayer or flexible solar cells. Herein, the formation of CsPbX3 perovskites at room‐temperature (RT) induced by dimethylsulphoxide (DMSO) coordination is reported. It is further found that a RT solvent (DMSO) annealing (RTSA) treatment is valid to control the perovskite crystallization dynamics, leading to uniform and void‐free films, and consequently a maximum power conversion efficiency (PCE) of 6.4% in the device indium tin oxide (ITO)/NiO x /RT‐CsPbI2Br/C60/Bathocuproine (BCP)/Ag, which is, as far as it is known, the first report of RT solution‐processed CsPbX3‐based perovskite solar cells (PSCs). Moreover, the efficiency can be boosted up to 10.4% by postannealing the RTSA‐treated perovskite film at an optimal temperature of 120 °C. Profiting from the moderate temperature, flexible PSCs are also demonstrated with a maximum PCE of 7.3% for the first time. These results may stimulate further development of all‐inorganic CsPbX3 perovskites and their application in flexible electronics.  相似文献   

18.
Although perovskite solar cells (PSCs) have emerged as a promising alternative to widely used fossil fuels, the involved high‐temperature preparation of metal oxides as a charge transport layer in most state‐of‐the‐art PSCs has been becoming a big stumbling block for future low‐temperature and large‐scale R2R manufacturing process. Such an issue strongly encourages scientists to find new type of materials to replace metal oxides. Except for expensive PC61BM with unmanageable morphology and electrical properties, the past investigation on the development of low‐temperature‐processed and highly efficient electron transport layers (ETLs) has met some mixed success. In order to further enhance the performance of all‐solution‐processed PSCs, we propose a novel n‐type sulfur‐containing small molecule hexaazatrinaphtho[2,3‐c][1,2,5]thiadiazole (HATNT) with high electron mobility up to 1.73 × 10?2 cm2 V?1 s?1 as an ETL in planar heterojunction PSCs. A high power conversion efficiency of 18.1% is achieved, which is fully comparable with the efficiency from the control device fabricated with PC61BM as ETL. This superior performance mainly attributes from more effective suppression of charge recombination at the perovskite/HATNT interface than that between the perovskite and PC61 BM. Moreover, high electron mobility and strong interfacial interaction via S? I or S? Pb bonding should be also positive factors. Significantly, our results undoubtedly enable new guidelines in exploring n‐type organic small molecules for high‐performance PSCs.  相似文献   

19.
All‐perovskite multijunction photovoltaics, combining a wide‐bandgap (WBG) perovskite top solar cell (EG ≈1.6–1.8 eV) with a low‐bandgap (LBG) perovskite bottom solar cell (EG < 1.3 eV), promise power conversion efficiencies (PCEs) >33%. While the research on WBG perovskite solar cells has advanced rapidly over the past decade, LBG perovskite solar cells lack PCE as well as stability. In this work, vacuum‐assisted growth control (VAGC) of solution‐processed LBG perovskite thin films based on mixed Sn–Pb perovskite compositions is reported. The reported perovskite thin films processed by VAGC exhibit large columnar crystals. Compared to the well‐established processing of LBG perovskites via antisolvent deposition, the VAGC approach results in a significantly enhanced charge‐carrier lifetime. The improved optoelectronic characteristics enable high‐performance LBG perovskite solar cells (1.27 eV) with PCEs up to 18.2% as well as very efficient four‐terminal all‐perovskite tandem solar cells with PCEs up to 23%. Moreover, VAGC leads to promising reproducibility and potential in the fabrication of larger active‐area solar cells up to 1 cm2.  相似文献   

20.
To realize high power conversion efficiencies (PCEs) in green‐solvent‐processed all‐polymer solar cells (All‐PSCs), a long alkyl chain modified perylene diimide (PDI)‐based polymer acceptor PPDIODT with superior solubility in nonhalogenated solvents is synthesized. A properly matched PBDT‐TS1 is selected as the polymer donor due to the red‐shifted light absorption and low‐lying energy level in order to achieve the complementary absorption spectrum and matched energy level between polymer donor and polymer acceptor. By utilizing anisole as the processing solvent, an optimal efficiency of 5.43% is realized in PBDT‐TS1/PPDIODT‐based All‐PSC with conventional configuration, which is comparable with that of All‐PSCs processed by the widely used binary solvent. Due to the utilization of an inverted device configuration, the PCE is further increased to over 6.5% efficiency. Notably, the best‐performing PCE of 6.58% is the highest value for All‐PSCs employing PDI‐based polymer acceptors and green‐solvent‐processed All‐PSCs. The excellent photovoltaic performance is mainly attributed to a favorable vertical phase distribution, a higher exciton dissociation efficiency (Pdiss) in the blend film, and a higher electrode carrier collection efficiency. Overall, the combination of rational molecular designing, material selection, and device engineering will motivate the efficiency breakthrough in green‐solvent‐processed All‐PSCs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号