Photoconductivity is demonstrated with monodispersed HgSe colloidal quantum dots that are illuminated with radiation resonant with 1S(e)-1P(e) intraband electronic absorption, between 3 and 5 μm. A doping of two electrons per dot gives the lowest dark current, and a detectivity of 8.5 × 10(8) Jones is obtained at 80 K. Photoluminescence of the intraband transition is also observed. The detector properties are discussed in terms of the measured photoluminescence quantum yield, the electron mobility in the 1P(e) state, and the responsivity. The intraband photoresponse allows to fully harness the quantum confined states in colloidal nanostructures, extending the prior limited use of interband transition.
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http://dx.doi.org/10.1021/nn505092a | DOI Listing |
The construction of an admirable hybrid bulk-heterojunction (HBH) can benefit the performance of optoelectronic devices through efficient charge separation and transportation. However, the present HBH structure still suffers from complicated layer-by-layer ligand exchanges during device fabrication. In this work, we apply a liquid phase exchange strategy in mixed colloidal hybrids composed of quantum dots (QDs) and nanotetrapods (NTs) and construct low-cost flexible self-powered infrared photodetectors with a carbon electrode.
View Article and Find Full Text PDFAdv Mater
January 2025
Institute for Advanced Materials & Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China.
Laboratory-scale spin-coating techniques are widely employed for fabricating small-size, high-efficiency perovskite solar cells. However, achieving large-area, high-uniformity perovskite films and thus high-efficiency solar cell devices remain challenging due to the complex fluid dynamics and drying behaviors of perovskite precursor solutions during large-area fabrication processes. In this work, a high-quality, pinhole-free, large-area FAPbI perovskite film is successfully obtained via scalable blade-coating technology, assisted by a novel bidirectional Marangoni convection strategy.
View Article and Find Full Text PDFNano Lett
January 2025
State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu Tian Road, Shanghai 200083, China.
Enhancing photoluminescence (PL) efficiency in colloidal quantum dots is pivotal for next-generation near-infrared photodetectors, imaging systems, and photonic devices. Conventional methods, especially metal-based plasmonic structures, suffer from large optical losses, which limits their practical use. Here, we introduce a quasi-bound state in the continuum (quasi-BIC) metasurface on a silicon-on-insulator platform, tailored to provide high-quality factor resonances with minimized losses.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
The tunability of the energy bandgap in the near-infrared (NIR) range uniquely positions colloidal lead sulfide (PbS) quantum dots (QDs) as a versatile material to enhance the performance of existing perovskite and silicon solar cells in tandem architectures. The desired narrow bandgap (NBG) PbS QDs exhibit polar (111) and nonpolar (100) terminal facets, making effective surface passivation through ligand engineering highly challenging. Despite recent breakthroughs in surface ligand engineering, NBG PbS QDs suffer from uncontrolled agglomeration in solid films, leading to increased energy disorder and trap formation.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Institute of Optoelectronic Materials and Devices, College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018 PR China. Electronic address:
Red light emitting perovskite quantum dot (PQD) glass, with narrow-band emission and excellent stability, holds great potential for applications in liquid crystal displays. However, its low photoluminescence quantum yield (PLQY) remains the biggest obstacle limiting its practical application. Additionally, the mechanism behind the enhancement of the PLQY is not well understood, which restricts the further improvement of the PLQY in red light emitting PQD glass.
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