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- 摘要
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- 实验方案
- 产品
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Selfa??Additive Lowa??Dimensional Ruddlesdena??Popper Perovskite by the Incorporation of Glycine Hydrochloride for Higha??Performance and Stable Solar Cells
摘要： The recent rise of low-dimensional Ruddlesden–Popper (RP) perovskites is notable for superior humidity stability, however they suffer from low power conversion efficiency (PCE). Suitable organic spacer cations with special properties display a critical effect on the performance and stability of perovskite solar cells (PSCs). Herein, a new strategy of designing self-additive low-dimensional RP perovskites is first proposed by employing a glycine salt (Gly+) with outstanding additive effect to improve the photovoltaic performance. Due to the strong interaction between CO and Pb2+, the Gly+ can become a nucleation center and be beneficial to uniform and fast growth of the Gly-based RP perovskites with larger grain sizes, leading to reduced grain boundary and increased carrier transport. As a result, the Gly-based self-additive low-dimensional RP perovskites exhibit remarkable photoelectric properties, yielding the highest PCE of 18.06% for Gly (n = 8) devices and 15.61% for Gly (n = 4) devices with negligible hysteresis. Furthermore, the Gly-based devices without encapsulation show excellent long-term stability against humidity, heat, and UV light in comparison to BA-based low-dimensional PSCs. This approach provides a feasible design strategy of new-type low-dimensional RP perovskites to obtain highly efficient and stable devices for next-generation photovoltaic applications.
关键词： low-dimensional perovskites,high-performance solar cells,self-additive effect,stable solar cells,glycine hydrochloride
更新于2025-09-23 15:19:57
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Solutiona??Processed Higha??Quality Cesium Lead Bromine Perovskite Photodetectors with High Detectivity for Application in Visible Light Communication
摘要： Cesium lead bromide (CsPbBr3) perovskite photodetectors (PDs) are attractive for applications in visible light communication (VLC) due to ultra-high detectivity and fast response speed. However, the fabrication of high-quality CsPbBr3 polycrystalline films using solution-based process is very challenging. Due to the low solubility of CsBr in precursor solutions, solution-processed CsPbBr3 films are typically discontinuous and porous, hindering the performance of resulting PDs. Herein, a facile and modified sequential spin-coating method is introduced to prepare high-crystallinity, pinhole-free CsPb2Br5-CsPbBr3 perovskite films with an average grain size of ≈1 μm. The hole-transport-layer-free (HTL-free) PDs based on the CsPb2Br5-CsPbBr3 perovskite films show high performance parameters, including the responsivity of 0.11 A W?1, the detectivity of 1.4 × 1012 Jones, a linear dynamic range of 128.6, and an on/off ratio of 1.5 × 106. The PDs outperform other HTL-free perovskite PDs and are comparable to the p–i–n perovskite PDs reported in the literature. In addition, the high-performance CsPb2Br5-CsPbBr3 PDs are applied in VLC by using the PD as a self-powered signal receiver of voice commands in a simulated room. This work uniquely combines the features of high-performance self-powered perovskite PDs with VLC techniques, paving the path to wide applications of all-inorganic perovskite PDs.
关键词： CsPb2Br5-CsPbBr3,perovskites,self-powered photodetectors,visible light communication
更新于2025-09-23 15:19:57
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A Study of Eu Doping in Nanolayers of CsPbBr <sub/>3</sub> using Ab Initio Calculations to Understand <i>fa??f</i> Transitions in Eu <sup>3+</sup> -Doped Nanocrystals for Light-Emitting Diodes
摘要： Recent experiments on Eu doped nanocrystals of CsPbX3 (X = Cl, Br) show that Eu exists in 3+ oxidation state even though it substitutes Pb which is in 2+ state in these perovskites. Therefore, the question arises, what is it that leads to the formation of Eu3+ in nanocrystals of these materials? In order to understand this, we have studied the doping of Eu in a slab (~1.8 nm thick) of CsPbBr3 from ab initio calculations and explored various possibilities that could lead to the formation of Eu3+ and the occurrence of f-f transitions. These include: 1) the presence of a Cs vacancy, 2) the existence of H or OH due to moisture, 3) substitution of O at a surface halogen site, and 4) the possibility of excess halogen around Eu. It is found that the presence of surface oxygen is the most likely reason for the observation of Eu3+ in these nanolayers. Our results show the presence of partially occupied spin-up f states and 6.48 μB magnetic moment on Eu that could lead to the possibility of f-f transition in these doped systems. A similar result has also been obtained for Eu doped in CsPbCl3 nanolayers. The calculated change in energy when defects/impurities are present gives favourable indication of finding H, OH, and Br as interstitials and O as substitutional entities, but Cs vacancy is unlikely. Additionally, we find that the doping of Eu in nanolayers does not affect the atomic structure and the cost of doping is also very small making these perovskites very promising materials for light emitting diodes and other solid-state lighting applications.
关键词： Two-dimensional systems,Light emitting diodes,Solid state lighting,Density functional theory,Metal-halide perovskites,Nanolayers,Defects,f-f transitions
更新于2025-09-23 15:19:57
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Firsta??principles Investigation of the Structural, Elastic, Electronic, and Optical Properties of ?±a?? and ?2a??SrZrS3: Implications for Photovoltaic Applications
摘要： Transition metal perovskite chalcogenides are attractive solar absorber materials for renewable energy applications. Herein, we present the first–principles screened hybrid density functional theory analyses of the structural, elastic, electronic and optical properties of the two structure modifications of strontium zirconium sulfide (needle–like α–SrZrS3 and distorted β–SrZrS3 phases). Through the analysis of the predicted electronic structures, we show that both α– and β–SrZrS3 materials are direct band gaps absorbers, with calculated band gaps of 1.38, and 1.95 eV, respectively, in close agreement with estimates from diffuse–reflectance measurements. A strong light absorption in the visible region is predicted for the α– and β–SrZrS3, as reflected in their high optical absorbance (in the order of 105 cm?1), with the β–SrZrS3 phase showing stronger absorption than the α–SrZrS3 phase. We also report the first theoretical prediction of effective masses of photo‐generated charge carriers in α– and β–SrZrS3 materials. Predicted small effective masses of holes and electrons at the valence, and conduction bands, respectively, point to high mobility (high conductivity) and low recombination rate of photo‐generated charge carriers in α– and β–SrZrS3 materials, which are necessary for efficient photovoltaic conversion.
关键词： Solar cell,Optoelectronic properties,Density Functional Theory,chalcogenide perovskites,earth–abundant materials
更新于2025-09-23 15:19:57
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Lighta??Emitting Electrochemical Cells Based on Colora??Tunable Inorganic Colloidal Quantum Dots
摘要： Large-area, ultrathin light-emitting devices currently inspire architects and interior and automotive designers all over the world. Light-emitting electrochemical cells (LECs) and quantum dot light-emitting diodes (QD-LEDs) belong to the most promising next-generation device concepts for future flexible and large-area lighting technologies. Both concepts incorporate solution-based fabrication techniques, which makes them attractive for low cost applications based on, for example, roll-to-roll fabrication or inkjet printing. However, both concepts have unique benefits that justify their appeal. LECs comprise ionic species in the active layer, which leads to the omission of additional organic charge injection and transport layers and reactive cathode materials, thus LECs impress with their simple device architecture. QD-LEDs impress with purity and opulence of available colors: colloidal quantum dots (QDs) are semiconducting nanocrystals that show high yield light emission, which can be easily tuned over the whole visible spectrum by material composition and size. Emerging technologies that unite the potential of both concepts (LEC and QD-LED) are covered, either by extending a typical LEC architecture with additional QDs, or by replacing the entire organic LEC emitter with QDs or perovskite nanocrystals, still keeping the easy LEC setup featured by the incorporation of mobile ions.
关键词： organic electronics,perovskites,luminescence,light-emitting electrochemical cells,quantum dots
更新于2025-09-23 15:19:57
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Multifunctional Phosphorusa??Containing Lewis Acid and Base Passivation Enabling Efficient and Moisturea??Stable Perovskite Solar Cells
摘要： Multiple-cation lead mixed-halide perovskites (MLMPs) have been recognized as ideal candidates in perovskite solar cells in terms of high efficiency and stability due to decreased open-circuit voltage loss and suppressed yellow phase formation. However, they still suffer from an unsatisfactory long-term moisture stability. In this study, phosphorus-containing Lewis acid and base molecules are employed to improve device efficiency and stability based on their multifunction including recombination reduction, phase segregation suppression, and moisture resistance. The strong fluorine-containing Lewis acid treatment can achieve a champion PCE of 22.02%. Unencapsulated and encapsulated devices retain 63% and 80% of the initial efficiency after 14 days of aging under 75% and 85% relative humidity, respectively. The better passivation of Lewis acid implies more halide defects than Pb defects at the MLMP surface. This unbalanced defect type results from phase segregation that is the synergistic effect of Cs and halide ion migrations. Identifying defect type based on different passivation effects is beneficial to not only choose suitable passivators to boost the efficiency and slow down the moisture degradation of MLMP solar cells, but also to understand the mechanism of defect-assisted moisture degradation.
关键词： lewis acids,trap passivation,moisture stable solar cells,multiple-cation lead mixed-halide perovskites,phase segregation,lewis bases
更新于2025-09-23 15:19:57
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A Nontoxic Bifunctional (Anti)Solvent as Digestivea??Ripening Agent for Higha??Performance Perovskite Solar Cells
摘要： The preparation of high-quality perovskite films is important for achieving high-performance perovskite solar cells (PSCs). The effective balance between solvent and antisolvent is an essential factor for regulating high-quality perovskite film during the spin-coating and thermal-annealing steps. In this work, a greener, nonhalogenated, nontoxic bifunctional (anti)solvent, methyl benzoate (MB), is developed not only as an antisolvent to rapidly generate crystal seeds at the perovskite spin-coating step, but also as a digestive-ripening solvent for the perovskite precursors, which can prevent the loss of organic components during the thermal-annealing stage and effectively suppress the formation of miscellaneous lead halide phases. As a result, this novel bifunctional (anti)solvent is employed in planar n–i–p PSCs for engineering high-quality perovskite layers and thus achieving a power conversion efficiency up to 22.37% with negligible hysteresis and >1300 h stability. Moreover, due to the high boiling point and low-volatility characteristic of MB, high-performance PSCs are achieved reproducibly at different operating temperatures (22–34 °C). Therefore, this developed bifunctional solvent system can provide a promising platform toward globally upscaling and commercializing PSCs in all seasons and regions.
关键词： digestive ripening,antisolvents,methyl benzoate,perovskites,thermal annealing,solvents
更新于2025-09-23 15:19:57
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In Situ Formed Gradient Bandgapa??Tunable Perovskite for Ultrahigha??Speed Color/Spectruma??Sensitive Photodetectors via Electrona??Donor Control
摘要： Integration of various photodetectors with different light-sensitive materials and detection capacity is an inevitable way to achieve entire color/spectrum detection. However, the uneven capacity of each photodetector would drag the overall performance behind, especially the response speed. A response time down to nanosecond level has not previously been reported for a filter-free color/spectrum-sensitive photodetector, as far as is known. Here, a self-powered filterless color-sensitive photodetection array based on an in situ formed gradient perovskite absorber film with continuously tunable bandgap is demonstrated. Ultrahigh-speed response at nanosecond level is achieved in all the ingredient photodetectors. The junction capacitance being influenced by carrier concentration in the absorber is identified to be responsible for the detection speed. Without any optic or mechanical supporting system, the designed color detector exhibits an external quantum efficiency (EQE) up to 94% and a high spectral resolution of around 80 nm for the whole visible spectrum. This work offers a guidance to achieve fast response of perovskite-based photodetectors from the point of view of carrier-donor control and demonstrates a new avenue to establish color-sensitive photodetectors/spectrometers.
关键词： photodetectors,self-powered devices,color-sensitive photodetection,spectrum analysis,perovskites
更新于2025-09-23 15:19:57
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Nona??Preheating Processed Quasia??2D Perovskites for Efficient and Stable Solar Cells
摘要： Although the hot-casting (HC) technique is prevalent in developing preferred crystal orientation of quasi-2D perovskite films, the difficulty of accurately controlling the thermal homogeneity of substrate is unfavorable for the reproducibility of device fabrication. Herein, a facile and effective non-preheating (NP) film-casting method is proposed to realize highly oriented quasi-2D perovskite films by replacing the butylammonium (BA+) spacer partially with methylammonium (MA+) cation as (BA)2?x(MA)3+xPb4I13 (x = 0, 0.2, 0.4, and 0.6). At the optimal x-value of 0.4, the resultant quasi-2D perovskite film possesses highly orientated crystals, associated with a dense morphology and uniform grain-size distribution. Consequently, the (BA)1.6(MA)3.4Pb4I13-based solar cells yield champion efficiencies of 15.44% with NP processing and 16.29% with HC processing, respectively. As expected, the HC-processed device shows a poor performance reproducibility compared with that of the NP film-casting method. Moreover, the unsealed device (x = 0.4) displays a better moisture stability with respect to the x = 0 stored in a 65% ± 5% relative humility chamber.
关键词： solar cells,crystal orientation,quasi-2D perovskites,film casting
更新于2025-09-23 15:19:57
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Effect of temperature on the performance of perovskite solar cells
摘要： The poor stability of perovskite solar cells is a crucial obstacle for its commercial applications. Here, we investigate the thermal stability of the mixed cation organic–inorganic lead halide perovskites (FAPbI3)1?xMAPb(Br3?yCly)x films and devices in air atmosphere. The results show that with the increase of heat treatment from 25 to 250 °C, the MA-perovskite decomposed into PbI2 firstly and the efficiency of corresponding solar cells reduced linearly. For the perovskite film, the increased heat treatment temperature can bring the redshift of the absorption edge leading to the decrease of band gap from 1.569 to 1.508 eV and increase of defect density from 3.87 × 1017 cm?3 to 9.03 × 1017 cm?3. However, a proper heat treatment time (10 min) at certain temperature (85 °C) can passivate defects effectively and improve the efficiency to 16.50%, realizing a 15% relative improvement of average efficiency. This work reveals a detailed thermal decomposition behavior of perovskite material and solar cells, which may provide insights into the stability of perovskite solar cells.
关键词： defect passivation,heat treatment,perovskite solar cells,thermal stability,mixed cation organic–inorganic lead halide perovskites
更新于2025-09-23 15:19:57