- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Fluorinated fulleropyrrolidine as universal electron transport material for organic-inorganic and all-inorganic perovskite solar cells
摘要： [6,6]-Phenyl-C61-butyric acid methylester (PC61BM) has been widely used as electron transport material (ETM) for both organic-inorganic hybrid and all inorganic perovskite solar cells (PeSCs) with inverted structure. However, PC61BM still remains to be improved due to its low electrical conductivity and inferior passivation effect towards perovskite. In this work, we synthesize two perfluorophenyl-substituted fulleropyrrolidines, 2-(perfluorophenyl)-5-phenyl-C60-fulleropyrrolidine (FP-i) and 2,5-bis-(perfluorophenyl)-C60-fulleropyrrolidine (FP-ii) via a modified 1,3-dipolar cycloaddition reaction. FP-i and FP-ii are introduced into inverted PeSCs based on organic-inorganic hybrid and all inorganic perovskites (CH3NH3PbCl3-xIx and CsPbI2Br) as ETMs. The PeSCs based on FP-i and FP-ii display good photovoltaic performance and device stability, which are superior or comparable to those with PC61BM. The mechanism studies reveal that FP-i and FP-ii possess higher electrical conductivity, more significant passivation capacity and enhanced hydrophobicity but slightly lower low unoccupied molecular orbital (LUMO) levels. These results suggest that FP-i and FP-ii are universal ETMs for both organic-inorganic hybrid and all inorganic PeSCs, which are better or comparable to conventional ETM of PC61BM.
关键词： Inverted perovskite solar cell,Fullerene derivative,Passivation effect,Device stability,Electron transporting layer
更新于2025-09-16 10:30:52
-
Dibenzo[ <i>b,d</i> ]thiophene‐Cored Hole‐Transport Material with Passivation Effect Enabling the High Efficiency Planar <i>P‐I‐N</i> Perovskite Solar Cells with 83% Fill Factor
摘要： N2,N2,N8,N8-tetrakis(4-(methylthio)phenyl)dibenzo[b,d]thiophene-2,8-diamine (abbreviated as DBTMT) is synthesized from three commercial monomers, for the application as a promising dopant-free hole-transport material (HTM) in perovskite solar cells (pero-SCs). The intrinsic properties (optical properties and electronic energy levels, etc.) of DBTMT are investigated proving that DBTMT is a suitable HTM for the planar p-i-n pero-SCs. Champion power conversion efficiency (PCE) of the optimized pero-SCs (with structure as ITO/ pristine DBTMT/MAPbI3/C60/BCP/Ag), reaches 21.12% with a fill factor (FF) of 83.25%, which is among the highest PCE and FF for the planar p-i-n pero-SCs based on the dopant-free HTMs. The FTIR, the XRD and the XPS spectra of MAPbI3 and DBTMT-MAPbI3 films are monitored further, demonstrating that there is interaction between DBTMT and MAPbI3 at the interface through the sulphur atoms in DBTMT to passivate the defects, which is corresponding to the higher FF and PCE of the corresponding device.
关键词： planar p-i-n perovskite solar cells,hole-transport materials,passivation
更新于2025-09-12 10:27:22
-
Effect of energy transfer on the optical properties of surface-passivated perovskite films with CdSe/ZnS quantum dots
摘要： Surface passivation is an effective method to protect the surfaces and improve the luminescence properties of perovskite (PS) films. CdSe/ZnS core-shell quantum dots (QDs) have been employed for surface passivation of PS films because of their size-dependent tunable bandgaps. Herein, the energy transfer (ET) behavior of CH3NH3PbI2Br PS films covered with CdSe/ZnS QDs (QD/PS hybrid structures) is characterized by using photoluminescence (PL) and time-resolved PL spectroscopy. The PL decay time and the integrated PL intensity of the QD/PS hybrid structure increase compared with those of the bare PS films, owing to ET from the QDs to the PS and reduced charge traps. The ET efficiency increases from ~7% to 63% for the QD/PS hybrid structure when the core diameter of the QDs decreases from 6.5 to 2.7 nm, respectively. This can be explained by the charge transfer rate enhancement due to the control of energy level alignment of QDs. These results allow us to understand fundamental mechanisms such as ET from QDs to PS films as a function of the size of the QD.
关键词： CdSe/ZnS quantum dots,perovskite films,energy transfer,photoluminescence,surface passivation
更新于2025-09-12 10:27:22
-
Bright high-colour-purity deep-blue carbon dot light-emitting diodes via efficient edge amination
摘要： Deep-blue light-emitting diodes (LEDs) (emitting at wavelengths of less than 450 nm) are important for solid-state lighting, vivid displays and high-density information storage. Colloidal quantum dots, typically based on heavy metals such as cadmium and lead, are promising candidates for deep-blue LEDs, but these have so far had external quantum efficiencies lower than 1.7%. Here we present deep-blue light-emitting materials and devices based on carbon dots. The carbon dots produce emission with a narrow full-width at half-maximum (about 35 nm) with high photoluminescence quantum yield (70% ± 10%) and a colour coordinate (0.15, 0.05) closely approaching the standard colour Rec. 2020 (0.131, 0.046) specification. Structural and optical characterization, together with computational studies, reveal that amine-based passivation accounts for the efficient and high-colour-purity emission. Deep-blue LEDs based on these carbon dots display high performance with a maximum luminance of 5,240 cd m?2 and an external quantum efficiency of 4%, notably exceeding that of previously reported quantum-tuned solution-processed deep-blue LEDs.
关键词： carbon dots,deep-blue LEDs,amine-based passivation,external quantum efficiency,high-colour-purity
更新于2025-09-12 10:27:22
-
Stable Triple Cation Perovskite Precursor for Highly Efficient Perovskite Solar Cells Enabled by Interaction with 18C6 Stabilizer
摘要： Triple cation perovskites (Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3) have received lots of attention owing to the excellent stability and photovoltaic performance. However, the development toward efficient solar cells has been significantly impeded by its intrinsic precursor instability, as well as defective crystal surface. Herein, a strategy for introducing the additive of 1,4,7,10,13,16-hexaoxacyclooctadecane (18C6) in the precursor solution, rendering an excellent stability of more than one month, and the defect passivation effect on the crystal surface are demonstrated. In those perovskite solar cells, a power conversion efficiency of 20.73% has been achieved with a substantially improved open-circuit voltage and fill factor. As evidenced by the density functional theory calculations, the fundamental reason relating to the enhanced performance is found to be the interaction effect between the 18C6 and cations, and in particular the formation of the 18C6/Pb complex. This finding represents an alternative strategy for achieving a stable precursor solution and efficient perovskite solar cells.
关键词： 18-crown-6,passivation,precursor stability,density functional theory
更新于2025-09-12 10:27:22
-
Improved open-circuit voltage and ambient stability of CsPbI2Br perovskite solar cells by incorporating CH3NH3Cl
摘要： Inorganic cesium metal halide perovskites have gained research interest as absorbers in perovskite solar cells due to their superior thermal stability. Among these, CsPbI2Br, with a narrower band gap than CsPbBr3 and a better phase stability than CsPbI3, has received tremendous interest of the researchers. However, CsPbI2Br takes adverse phase transfer easily with an exposure to the water vapor in ambient air which not only brings inconvenience for researches but also puts forward very high requirement for encapsulation. Herein, a dense and uniform film is obtained by incorporating hydrophobic CH3NH3Cl (MACl) into the precursor solution. Being attributed to a good passivation effect, the defect density is decreased from 3.12 × 1016 to 1.49 × 1016 cm-3 and the average photoluminescence lifetime is increased from 8.84 to 20.6 ns. The photovoltaic device achieves a high open-circuit voltage of 1.22 V based on optimized MACl-doped film and accordingly a higher power conversion efficiency (PCE) of 12.9% which is 21.7% higher than the pristine CsPbI2Br device with PCE of 10.6%. In addition, the ambient stability of MACl-doped device has been enhanced, which is greatly attributed to the hydrophobic properties of MACl. This work provides a clue to improve ambient stability of inorganic perovskite solar cells and inspires toward further development of this material.
关键词： Passivation,Ambient stability,CsPbI2Br perovskite,MACl
更新于2025-09-12 10:27:22
-
Hexylammonium Iodide Derived Two-Dimensional Perovskite as Interfacial Passivation Layer in Efficient Two-Dimensional/Three-Dimensional Perovskite Solar Cells
摘要： Defects locating within grain boundaries or on the film surface, especially organic cation vacancies and iodine vacancies make the fabrication of perovskite solar cells (PSCs) with superior performance a challenge. Organic ammonium iodide is a promising candidate and has been frequently used to passivate these defects by forming two-dimensional (2D) perovskite. In this work, it is found that the chain length of organic ammonium iodide is a crucial factor on the defect passivation effect. Compared to butylammonium iodide (BAI), hexylammonium iodide (HAI) derived 2D perovskite is more efficient in decreasing interfacial defects, resulting in a notably enhanced photoluminescence lifetime and a more suppressed interfacial charge recombination process. As a consequence, the ultimate power conversion efficiency (PCE) has reached 20.62% (3D+HAI) as compared to 18.83% (3D). Moreover, the long-term durability of the corresponding PSCs against humidity and heat is simultaneously improved. This work once again demonstrates that 2D/3D structure is promising for further improving the PCE and stability of PSCs.
关键词： perovskite solar cell,organic ammonium iodide,stability,interfacial passivation,2D/3D stacking structure
更新于2025-09-12 10:27:22
-
Improved Surface Passivation by Wet Texturing, Ozone‐Based Cleaning, and Plasma‐Enhanced Chemical Vapor Deposition Processes for High‐Efficiency Silicon Heterojunction Solar Cells
摘要： This paper reports on the development of wet chemical processes varying the texturing and cleaning of the silicon surfaces, reducing process time and the amount of chemicals to obtain the same cleaning quality. Additionally, two different amorphous silicon (a-Si:H) passivation stacks are discussed in this paper demonstrating an improvement of the open circuit voltage, Voc, by 15 mV. Implementing these wet chemistry improvements combined with optimized process conditions for the passivating a-Si:H layers deposited by plasma enhanced chemical vapor deposition (PECVD), allowed us to obtain high efficiency devices both in small and full-area solar cells. On 6-inch full-area solar cells (215.3 cm2 aperture area) open circuit voltages, fill factors and efficiency values of 738 mV, 81.4% and 23.2% were obtained, respectively; for 4 cm2 cell size the best obtained values in equivalent solar cells were 741 mV, 80.6% and 23.2%.
关键词： silicon heterojunction solar cells,texturing,ozone cleaning,surface passivation
更新于2025-09-12 10:27:22
-
Mechanism of PbI2 situ-passivated perovskite films for enhancing performance of perovskite solar cells
摘要： Perovskite solar cells have brought tremendous research interests because of their tolerance of defects, low cost, and facile processing. In perovskite solar cells devices, PbI2 has been utilized to passivate defects at perovskite films surface and grain boundaries, yet a systematic mechanism of PbI2 situ-passivating for enhancing the efficiency has not been fully explored. Here, this work systematically studies the role of the precise PbI2 ratio, and the PbI2 situ-passivation mechanism based on trap density, carrier lifetime, and Fermi level etc. This study finds that the appropriate ratio of I:Pb is around 2.57:1 using energy dispersive spectroscopy. After the moderate excess PbI2 situ-passivating, the trap density is reduced from 6.12 × 1016 cm-3 to 3.38 × 1016 cm-3, and the carrier lifetime is extended from 168.35 ps to 368.77 ps by using femtosecond transient absorption spectroscopy. This result indicates that the moderate excess PbI2 situ-passivation can reduce the trap density and suppress non-radiative recombination. The efficiency of solar cell has realized a nearly 11.3% improvement of 19.55% for the I:Pb ratio of 2.57:1 compared with 2.69:1. It demonstrates that the efficiency can be enhanced effectively by PbI2 situ-passivation.
关键词： SnO2,EDS-mapping,transient absorption spectroscopy,perovskite solar cells,PbI2,passivation mechanism
更新于2025-09-12 10:27:22
-
Facile Formation of 2D-3D Heterojunctions on Perovskite Thin Film Surfaces for Efficient Solar Cells
摘要： The interfaces between perovskite and charge transport layers greatly impact the device efficiency and stability of perovskite solar cells (PSCs). Inserting an ultrathin wide bandgap layer between perovskite and hole transport layers (HTL) has recently been shown as an effective strategy to enhance device performance. Herein, a small amount of organic halide salt, N,N’-dimethylethylene-1,2-diammonium iodide, is used to create 2D-3D heterojunctions on MAPbI3 thin film surfaces by facile solution processing. The formation of ultrathin wide bandgap 2D perovskite layer on top of 3D MAPbI3 changes the morphological and photophysical properties of perovskite thin films, effectively reduces the surface defects, and suppresses the charge recombination in the interfaces between perovskite and HTL. As a result, a power conversion efficiency of ~ 20.2%, with an open circuit voltage of 1.14 V, a short-circuit current density of 22.57 mA cm-2, and a fill factor of 0.78, is achieved for PSCs with enhanced stability.
关键词： Perovskite solar cells,2D-3D heterojunctions,interface engineering,stability,surface passivation
更新于2025-09-12 10:27:22