共查询到10条相似文献,搜索用时 140 毫秒
1.
Daehee Seol Ahreum Jeong Man Hyung Han Seongrok Seo Tae Sup Yoo Woo Seok Choi Hyun Suk Jung Hyunjung Shin Yunseok Kim 《Advanced functional materials》2017,27(37)
Organic–inorganic hybrid perovskite solar cells are attracting the attention of researchers owing to the high level of performance they exhibit in photovoltaic device applications. However, the attainment of an even higher level of performance is hindered by their anomalous current–voltage (I–V) hysteresis behavior. Even though experimental and theoretical studies have suggested that the perovskite materials may have a ferroelectric nature, it is still far from being fully understood. In this study, the origin of the hysteresis behavior in CH3NH3PbI3 perovskite thin films is investigated. The behavior of ferroelectricity using piezoresponse force microscopy is first examined. Then, by comparing the scan‐rate‐dependent nano/macroscopic I–V curves, it is found that ion migration assisted by the grain boundaries is a dominant origin of I–V hysteresis from a macroscopic viewpoint. Consequently, the observations suggest that, even though ferroelectricity exists in the CH3NH3PbI3 perovskite materials, ion migration primarily contributes to the macroscopic I–V hysteresis. The presented results can provide fundamental guidelines to the resolution of hysteresis issues in organic–inorganic hybrid perovskite materials. 相似文献
2.
Morphological Control for High Performance,Solution‐Processed Planar Heterojunction Perovskite Solar Cells 下载免费PDF全文
Giles E. Eperon Victor M. Burlakov Pablo Docampo Alain Goriely Henry J. Snaith 《Advanced functional materials》2014,24(1):151-157
Organometal trihalide perovskite based solar cells have exhibited the highest efficiencies to‐date when incorporated into mesostructured composites. However, thin solid films of a perovskite absorber should be capable of operating at the highest efficiency in a simple planar heterojunction configuration. Here, it is shown that film morphology is a critical issue in planar heterojunction CH3NH3PbI3‐xClx solar cells. The morphology is carefully controlled by varying processing conditions, and it is demonstrated that the highest photocurrents are attainable only with the highest perovskite surface coverages. With optimized solution based film formation, power conversion efficiencies of up to 11.4% are achieved, the first report of efficiencies above 10% in fully thin‐film solution processed perovskite solar cells with no mesoporous layer. 相似文献
3.
Unveiling a Key Intermediate in Solvent Vapor Postannealing to Enlarge Crystalline Domains of Organometal Halide Perovskite Films 下载免费PDF全文
Shuang Xiao Yang Bai Xiangyue Meng Teng Zhang Haining Chen Xiaoli Zheng Chen Hu Yongquan Qu Shihe Yang 《Advanced functional materials》2017,27(12)
Hybrid organic/inorganic perovskite solar cells (PSCs) have shown great potential in meeting the future challenges in energy and environment. Solvent‐vapor‐assisted posttreatment strategies are developed to improve the perovskite film quality for achieving higher efficiency. However, the intrinsic working mechanisms of these strategies have not been well understood yet. This study identifies an MA2Pb3I8(DMSO)2 intermediate phase formed during the annealing process of methylammonium lead triiodide in dimethyl sulfoxide (DMSO) atmosphere and located the reaction sites at perovskite grain boundaries by observing and rationalizing the growth of nanorods of the intermediate. This enables us to propose and validate an intermediate‐assisted grain‐coarsening model, which highlights the activation energy reduction for grain boundary migration. Leveraging this mechanism, this study uses MABr/DMSO mixed vapor to further enhance grain boundary migration kinetics and successfully obtain even larger grains, leading to an impressive improvement in power conversion efficiency (17.64%) relative to the pristine PSCs (15.13%). The revelation of grain boundary migration‐assisted grain growth provides a guide for the future development of polycrystalline perovskite thin‐film solar cells. 相似文献
4.
Ibrahima Ka Ivy M. Asuo Suchismita Basu Paul Fourmont Dawit M. Gedamu Alain Pignolet Sylvain G. Cloutier Riad Nechache 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(38)
The morphology of hybrid organic–inorganic perovskite films is known to strongly affect the performance of perovskite‐based solar cells. CH3NH3PbI3‐xClx (MAPbI3‐xClx) films have been previously fabricated with 100% surface coverage in glove boxes. In ambient air, fabrication generally relies on solvent engineering to obtain compact films. In contrast, this work explores the potential of altering the perovskites microstructure for solar cell engineering. This work starts with CH3NH3PbI3‐xClx, films with grain morphology carefully controlled by varying the deposition speed during the spin‐coating process to fabricate efficient and partially transparent solar cells. Devices produced with a CH3NH3PbI3‐xClx film and a compact thick top gold electrode reach a maximum efficiency of 10.2% but display a large photocurrent hysteresis. As it is demonstrated, the introduction of different concentrations of bromide in the precursor solution addresses the hysteresis issues and turns the film morphology into a partially transparent interconnected network of 1D microstructures. This approach leads to semitransparent solar cells with negligible hysteresis and efficiencies up to 7.2%, while allowing average transmission of 17% across the visible spectrum. This work demonstrates that the optimization of the perovskites composition can mitigate the hysteresis effects commonly attributed to the charge trapping within the perovskite film. 相似文献
5.
Chang Liu Kai Wang Chao Yi Xiaojun Shi Adam W. Smith Xiong Gong Alan J. Heeger 《Advanced functional materials》2016,26(1):101-110
In this work, alcohol‐vapor solvent annealing treatment on CH3NH3PbI3 thin films is reported, aiming to improve the crystal growth and increase the grain size of the CH3NH3PbI3 crystal, thus boosting the performance of perovskite photovoltaics. By selectively controlling the CH3NH3I precursor, larger‐grain size, higher crystallinity, and pinhole‐free CH3NH3PbI3 thin films are realized, which result in enhanced charge carrier diffusion length, decreased charge carrier recombination, and suppressed dark currents. As a result, over 43% enhanced efficiency along with high reproducibility and eliminated photocurrent hysteresis behavior are observed from perovskite hybrid solar cells (pero‐HSCs) where the CH3NH3PbI3 thin films are treated by methanol vapor as compared with that of pristine pero‐HSCs where the CH3NH3PbI3 thin films are without any alcohol vapor treatment. In addition, the dramatically restrained dark currents and raised photocurrents give rise to over ten times enhanced detectivities for perovskite hybrid photodetectors, reaching over 1013 cm Hz1/2 W?1 (Jones) from 375 to 800 nm. These results demonstrate that the method provides a simple and facile way to boost the device performance of perovskite photovoltaics. 相似文献
6.
Qikun Hu Ehsan Rezaee Wangping Xu Rajendran Ramachandran Qian Chen Hu Xu Tarek EL-Assaad Dominic V. McGrath Zong-Xiang Xu 《Small (Weinheim an der Bergstrasse, Germany)》2021,17(1):2005216
Semiconducting molecules have been employed to passivate traps extant in the perovskite film for enhancement of perovskite solar cells (PSCs) efficiency and stability. A molecular design strategy to passivate the defects both on the surface and interior of the CH3NH3PbI3 perovskite layer, using two phthalocyanine (Pc) molecules (NP-SC6-ZnPc and NP-SC6-TiOPc) is demonstrated. The presence of lone electron pairs on S, N, and O atoms of the Pc molecular structures provides the opportunity for Lewis acid–base interactions with under-coordinated Pb2+ sites, leading to efficient defect passivation of the perovskite layer. The tendency of both NP-SC6-ZnPc and NP-SC6-TiOPc to relax on the PbI2 terminated surface of the perovskite layer is also studied using density functional theory (DFT) calculations. The morphology of the perovskite layer is improved due to employing the Pc passivation strategy, resulting in high-quality thin films with a dense and compact structure and lower surface roughness. Using NP-SC6-ZnPc and NP-SC6-TiOPc as passivating agents, it is observed considerably enhanced power conversion efficiencies (PCEs), from 17.67% for the PSCs based on the pristine perovskite film to 19.39% for NP-SC6-TiOPc passivated devices. Moreover, PSCs fabricated based on the Pc passivation method present a remarkable stability under conditions of high moisture and temperature levels. 相似文献
7.
Wenzhan Xu Tao Zhu Yongrui Yang Luyao Zheng Lei Liu Xiong Gong 《Advanced functional materials》2020,30(30)
Perovskite photovoltaics have drawn great attention in both academic and industrial sectors in the past decade. To date, impressive device performance has been achieved in state‐of‐the‐art device architectures through morphological manipulation and generic interface engineering. In this study, enhanced device performance of perovskite photovoltaics by magnetic field‐aligned CH3NH3PbI3‐mixed Fe3O4 magnetic nanoparticles (CH3NH3PbI3:Fe3O4) composite thin films is reported. It is found that magnetic field‐aligned CH3NH3PbI3:Fe3O4 composite thin films possess superior film morphology, boosted and balanced charge carrier mobility, and suppressed trap density. Moreover, perovskite photovoltaics by magnetic field‐aligned CH3NH3PbI3:Fe3O4 composite thin films exhibit suppressed charge carrier recombination and shorter charge carrier extraction time. As a result, perovskite solar cells by magnetic field‐aligned CH3NH3PbI3:Fe3O4 composite thin films exhibit 20.23% power conversion efficiency with significantly reduced photocurrent hysteresis. Moreover, perovskite photodetectors by magnetic field‐aligned CH3NH3PbI3:Fe3O4 composite thin films exhibit a photoresponsivity of 858 mA W?1, a photodetectivity over 1013 Jones (1 Jones = 1 cm Hz1/2 W?1) and a linear dynamic range over 160 dB at room temperature. All these device performance parameters are significantly better than those by pristine CH3NH3PbI3 thin film. Thus, these studies provide a facile way to boost device performance of perovskite photovoltaics. 相似文献
8.
In this study, a facile and effective approach to synthesize high‐quality perovskite‐quantum dots (QDs) hybrid film is demonstrated, which dramatically improves the photovoltaic performance of a perovskite solar cell (PSC). Adding PbS QDs into CH3NH3PbI3 (MAPbI3) precursor to form a QD‐in‐perovskite structure is found to be beneficial for the crystallization of perovskite, revealed by enlarged grain size, reduced fragmentized grains, enhanced characteristic peak intensity, and large percentage of (220) plane in X‐ray diffraction patterns. The hybrid film also shows higher carrier mobility, as evidenced by Hall Effect measurement. By taking all these advantages, the PSC based on MAPbI3‐PbS hybrid film leads to an improvement in power conversion efficiency by 14% compared to that based on pure perovskite, primarily ascribed to higher current density and fill factor (FF). Ultimately, an efficiency reaching up to 18.6% and a FF of over ≈0.77 are achieved based on the PSC with hybrid film. Such a simple hybridizing technique opens up a promising method to improve the performance of PSCs, and has strong potential to be applied to prepare other hybrid composite materials. 相似文献
9.
Controllable Perovskite Crystallization by Water Additive for High‐Performance Solar Cells 下载免费PDF全文
Xiu Gong Meng Li Xiao‐Bo Shi Heng Ma Zhao‐Kui Wang Liang‐Sheng Liao 《Advanced functional materials》2015,25(42):6671-6678
A key issue for perovskite solar cells is the stability of perovskite materials due to moisture effects under ambient conditions, although their efficiency is improved constantly. Herein, an improved CH3NH3PbI3?xClx perovskite quality is demonstrated with good crystallization and stability by using water as an additive during crystal perovskite growth. Incorporating suitable water additives in N,N‐dimethylformamide (DMF) leads to controllable growth of perovskites due to the lower boiling point and the higher vapor pressure of water compared with DMF. In addition, CH3NH3PbI3?xClx · nH2O hydrated perovskites, which can be resistant to the corrosion by water molecules to some extent, are assumed to be generated during the annealing process. Accordingly, water additive based perovskite solar cells present a high power conversion efficiency of 16.06% and improved cell stability under ambient conditions compared with the references. The findings in this work provide a route to control the growth of crystal perovskites and a clue to improve the stability of organic–inorganic halide perovskites. 相似文献
10.
SrCl2 Derived Perovskite Facilitating a High Efficiency of 16% in Hole‐Conductor‐Free Fully Printable Mesoscopic Perovskite Solar Cells 下载免费PDF全文
Hua Zhang Huan Wang Spencer T. Williams Dehua Xiong Wenjun Zhang Chu‐Chen Chueh Wei Chen Alex K.‐Y. Jen 《Advanced materials (Deerfield Beach, Fla.)》2017,29(15)
Despite the breakthrough of over 22% power conversion efficiency demonstrated in organic–inorganic hybrid perovskite solar cells (PVSCs), critical concerns pertaining to the instability and toxicity still remain that may potentially hinder their commercialization. In this study, a new chemical approach using environmentally friendly strontium chloride (SrCl2) as a precursor for perovskite preparation is demonstrated to result in enhanced device performance and stability of the derived hole‐conductor‐free printable mesoscopic PVSCs. The CH3NH3PbI3 perovskite is chemically modified by introducing SrCl2 in the precursor solution. The results from structural, elemental, and morphological analyses show that the incorporation of SrCl2 affords the formation of CH3NH3PbI3(SrCl2)x perovskites endowed with lower defect concentration and better pore filling in the derived mesoscopic PVSCs. The optimized compositional CH3NH3PbI3(SrCl2)0.1 perovskite can substantially enhance the photovoltaic performance of the derived hole‐conductor‐free device to 15.9%, outperforming the value (13.0%) of the pristine CH3NH3PbI3 device. More importantly, the stability of the device in ambient air under illumination is also improved. 相似文献