Two-dimensional (2D) CsPbBr exhibits intriguing functions in enhancing the performance of optoelectronic devices in terms of environmental stability and luminescence properties when composited with other perovskites in different dimensionalities. We built a type I three-dimensional (3D) CsPbBr/2D CsPbBr heterojunction through phase transition where CsPbBr quantum dots in situ grew into 2D CsPbBr. A thorough growth mechanism study in combination with excited state dynamic investigations via femtosecond spectroscopy and first-principles calculations revealed that the type I hierarchy enhanced the stability of the heterojunction and spurred its luminous quantum yield by prolonging the lifetime of photogenerated carriers. Mixing the heterojunction with other phosphors yielded white-light-emitting diodes with a color rendering index of 94%. The work thus not only offered one new avenue for building heterojunctions by using the "soft crystal" nature of perovskites but also disentangled the enhanced luminescence mechanism of the heterojunction that can be harnessed for promising applications in the luminescence and display fields.
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http://dx.doi.org/10.1021/acs.jpclett.0c01757 | DOI Listing |
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December 2024
Institute of Polymer Optoelectronic Materials & Devices, Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials, State Key Laboratory of Luminescent Materials & Devices, South China University of Technology, Guangzhou, 510640, China.
Polymer hole transport materials offer significant efficiency and stability advantages for p-i-n perovskite solar cells. However, the energetic disorder of amorphous polymer hole transport materials not only limits carrier transport but also impedes contact between the polymer and perovskite, hindering the formation of high crystalline quality perovskites. Herein, a novel low energetic disordered polymer hole transport material, PF8ICz, featuring an indeno[3,2-b]carbazole unit with extended π-conjugation is designed and synthesized.
View Article and Find Full Text PDFSmall Methods
December 2024
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China.
The development of front-side pastes suitable for devices with high sheet resistance such as tunnel oxide passivated contact (TOPCon), is of great significance but remains a considerable challenge. The optimization of the Ag-Si contact interface is crucial for enhancing contact and improving the efficiency of these devices. This work investigates the front-side Ag pastes with low Al content (<2 wt.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Institute of Optoelectronics Technology, Key Laboratory of Luminescence and Optical Information, Beijing Jiaotong University, Beijing 100044, China.
This work explores the carrier recombination dynamics of AC-driven quantum dot (QD) light-emitting diodes (AC-QLEDs) and proposes their application in the field of electric field contactless detection. Different sequences of green QD (GQD)/red QD (RQD) bilayer thin films as the emission layer of AC-QLEDs were fabricated via film transfer printing to ensure the complete morphology of each layer. AC-QLEDs with the emission layer as the sequence of GQD + RQD (GR-QLEDs) show a significantly enhanced carrier recombination efficiency due to its stable energy level structure, achieving the highest peak brightness ever recorded for vertically emitting brightness of 1648.
View Article and Find Full Text PDFDalton Trans
December 2024
College of Optoelectronic Engineering, Chongqing University of Post and Telecommunications, 400065, People's Republic of China.
With many fascinating characteristics, such as color-tunability, narrow-band emission, and low-cost solution processability, all-inorganic lead halide perovskite quantum dots (QDs) have attracted keen attention for electroluminescent light-emitting diodes (QLEDs) and display applications. However, the performance of perovskite QLED devices is intrinsically limited by the inefficient electrical carrier transport capacity. Herein, one facile but effective method is proposed to enhance the perovskite QLED performance by incorporating a short carbon chain ligand of 2-phenethylammonium bromide (PEABr) to passivate the CsPbBr QD surface.
View Article and Find Full Text PDFJ Phys Chem Lett
December 2024
School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.
NiO is a wide-bandgap p-type metal oxide that has extensive applications in optoelectronics and photocatalysts. Understanding the carrier dynamics in p-type NiO is pivotal for optimizing device performance, yet they remain largely unexplored. In this study, we employed femtosecond transient absorption spectroscopy to delve into the dynamics of photogenerated carriers in NiO films containing distinct prominent native defects: undoped NiO with oxygen vacancies () and O-rich NiO (denoted as NiO) with nickel vacancies ().
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