- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Controlled crystallinity and morphologies of 2D Ruddlesden-Popper perovskite films grown without anti-solvent for solar cells
摘要： Two-dimensional (2D) Ruddlesden-Popper (RP) perovskite films have attracted considerable attention for the environmentally stable perovskite solar cells. However, there is a big space for improving the film crystallinity and its crystallographic orientation to enhance the efficiency of solar cells. In addition, the assistance of anti-solvent is commonly used to obtain a better crystallinity and orientation of 2D RP perovskite films. Nevertheless, the anti-solvent method produces a lot of volatile organic compounds toxic to human health and is challenging to control. Here, we prepared 2D RP perovskite (PEA)2(MA)4Pb5I16 (n = 5) films with the assistance of methylammonium chloride (MACl) additive via a simple one-step deposition method by avoiding anti-solvent treatment. The MACl additive is believed to induce the formation of an intermediate phase composed of perovskite crystals without annealing, which directly promotes the vertical alignment of 2D RP perovskite films on the substrate. The 2D RP films deposited on the mesoporous TiO2 electron transport layer showed high crystallinity and preferential vertical crystallographic orientation. The resulting devices exhibited a power conversion efficiency of 9.7%, much higher than that of the devices prepared without MACl (0.66%).
关键词： High efficiency,High crystallinity and preferential vertical orientation,Two-dimensional perovskite solar cells,No anti-solvent treatment,MACl additive
更新于2025-09-23 15:21:01
-
Light-Enhanced Ion Migration in Two-Dimensional Perovskite Single Crystals Revealed in Carbon Nanotubes/Two-Dimensional Perovskite Heterostructure and Its Photomemory Application
摘要： Two-dimensional (2D) hybrid perovskite sandwiched between two long-chain organic layers is an emerging class of low-cost semiconductor materials with unique optical properties and improved moisture stability. Unlike conventional semiconductors, ion migration in perovskite is a unique phenomenon possibly responsible for long carrier lifetime, current?voltage hysteresis, and low-frequency giant dielectric response. While there are many studies of ion migration in bulk hybrid perovskite, not much is known for its 2D counterparts, especially for ion migration induced by light excitation. Here, we construct an exfoliated 2D perovskite/carbon nanotube (CNT) heterostructure field effect transistor (FET), not only to demonstrate its potential in photomemory applications, but also to study the light induced ion migration mechanisms. We show that the FET I?V characteristic curve can be regulated by light and shows two opposite trends under different CNT oxygen doping conditions. Our temperature-dependent study indicates that the change in the I?V curve is probably caused by ion redistribution in the 2D hybrid perovskite. The first principle calculation shows the reduction of the migration barrier of I vacancy under light excitation. The device simulation shows that the increase of 2D hybrid perovskite dielectric constant (enabled by the increased ion migration) can change the I?V curve in the trends observed experimentally. Finally, the so synthesized FET shows the multilevel photomemory function. Our work shows that not only we could understand the unique ion migration behavior in 2D hybrid perovskite, it might also be used for many future memory function related applications not realizable in traditional semiconductors.
关键词： photomemory,carbon nanotube,ion migration,Two-dimensional perovskite,heterostructure
更新于2025-09-23 15:19:57
-
4-Aminoethyl Pyridine as a Bifunctional Spacer Cation for Efficient and Stable 2D Ruddlesden-Popper Perovskite Solar Cells
摘要： Two-dimensional (2D) Ruddlesden?Popper (RP) perovskites are attractive due to their appealing environmental stability. We demonstrate herein a spacer cation, 4-aminoethyl pyridine (4-AEP), for preparation of 2D RP perovskite films. The 4-AEP can not only act as a spacer cation, but also coordinate with the Pb2+ ions in PbI2 with the nitrogen atom on the pyridine ring. High-quality 2D RP perovskite films can thus be formed as the coordination interaction retards the crystallization rate of the 2D RP perovskites. As a result, the solar cell employing the (4-AEP)2MAn?1PbnI3n+1 (n=5) 2D perovskite achieves a power conversion efficiency (PCE) of 11.68% with good air stability, which is much better than the phenylethylamine spacer cation at the same conditions (PCE = 7.95%). This work provides a new idea for designing novel spacer cations towards efficient and stable 2D RP perovskite solar cells.
关键词： Two-dimensional perovskite,pyridine,spacer cation,perovskite solar cells,crystallization regulation
更新于2025-09-12 10:27:22
-
Efficient Quasi-Two-Dimensional Perovskite Light-Emitting Diodes with Improved Multiple Quantum Well Structure
摘要： Quasi-two-dimensional (quasi-2D) perovskites with a multiple quantum well structure can enhance the exciton binding energy and controllable quantum con?ne e?ect, which are attractive materials for e?cient perovskite light-emitting diodes (PeLEDs). However, the multiphase mixtures contained in these materials would cause nonradiative recombination at the perovskite ?lm surface. Here, a facile solution surface treatment is adopted to improve the multiple quantum well structure of the quasi-2D perovskite emitting layer, which can reduce the in?uence of defectinduced nonradiative recombination and the electric-?eld-induced dissociation of excitons for the PeLEDs. The improved multiple quantum well structure is veri?ed by UV absorption spectra and temperature-dependent photoluminescence spectra measurements. The photoluminescence quantum yield of the quasi-2D perovskite ?lm with surface treatment has been approximately increased by 200%. Meanwhile, the electroluminescence device achieves a current e?ciency of 45.9 cd/A.
关键词： electroluminescence,quasi-two-dimensional perovskite light-emitting diodes,surface treatment,multiple quantum well structure,photoluminescence quantum yield
更新于2025-09-12 10:27:22
-
Single Source Thermal Evaporation of Two-dimensional Perovskite Thin Films for Photovoltaic Applications
摘要： Hybrid two-dimensional (2D) halide perovskites has been widely studied due to its potential application for high performance perovskite solar cells. Understanding the relationship between microstructural and opto-electronic properties is very important for fabricating high-performance 2D perovskite solar cell. In this work, the effect of solvent annealing on grain growth was investigated to enhance the efficiency of photovoltaic devices with 2D perovskite films based on (BA)2(MA)3pb4i13 prepared by single-source thermal evaporation. Results show that solvent annealing with the introduction of solvent vapor can effectively enhance the crystallization of the (BA)2(MA)3pb4i13 thin films and produce denser, larger-crystal grains. The thin films also display a favorable band gap of 1.896 eV, which benefits for increasing the charge-diffusion lengths. The solvent-annealed (BA)2(MA)3pb4i13 thin-film solar cell prepared by single-source thermal evaporation shows an efficiency range of 2.54–4.67%. Thus, the proposed method can be used to prepare efficient large-area 2D perovskite solar cells.
关键词： solvent annealing,thermal evaporation,two-dimensional perovskite,photovoltaic applications,grain growth
更新于2025-09-11 14:15:04
-
High-performance lead-free two-dimensional perovskite photo transistors assisted by ferroelectric dielectrics
摘要： The purpose of this research was to understand the effect of a built-in ferroelectric field on the performance of two-dimensional (2D) lead-free perovskite material-based phototransistor applications. In this work, ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) and two-dimensional (2D) lead-free perovskite ((C6H5C2H4NH3)2SnI4) were utilized as a dielectric layer and a channel layer, respectively. We observed that large hysteresis was successfully eliminated in the transfer curve, as well as the subthreshold swing being significantly reduced by one order of magnitude after P(VDF-TrFE) was introduced as a dielectric layer. Under polarization ‘‘up’’ and ‘‘down’’ states, the device achieved a high photo-switching on/off ratio (4100) and a short photoresponse time (50 ms), respectively. In addition to that, the device also demonstrated a high responsivity of 14.57 A W?1 and a high detectivity of 1.74 × 1012 Jones under the polarization ‘‘up’’ state with an illumination intensity of 21 mW cm?2. In addition, low temperature solution-processed P(VDF-TrFE) and (C6H5C2H4NH3)2SnI4 (except for the contacts of Au electrodes) in this work are considered to be suitable and compatible for flexible-based phototransistor applications in the future.
关键词： lead-free,phototransistor,two-dimensional perovskite,ferroelectric dielectrics
更新于2025-09-09 09:28:46