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- 摘要
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Room Temperature Graphene Mid-Infrared Bolometer with a Broad Operational Wavelength Range
摘要： The last decade has witnessed the realization of numerous different types of graphene photodetectors with a strong focus on the visible and near-infrared spectral range, in which various high-performance photodetectors exist based on traditional materials such as silicon and III-V compound semiconductors. However, high-speed mid-infrared photodetection at room-temperature is still an unsolved challenge, despite its importance in applications such as security, sensing, and imaging. Here we address this challenge by demonstrating that high-quality graphene is an ideal high-speed bolometric material for the less-explored yet critical mid-infrared photodetection at room temperature, due to its broadband absorption, small heat capacity, and remarkably large temperature coefficient of resistance (TCR) of up to around 1% per Kelvin, which is comparable to that of commercial bolometric materials. We demonstrate a device based on graphene encapsulated in hexagonal boron nitride (hBN) exhibiting decent extrinsic responsivities of 5.1-1.4 mA/W in 3.4-12 μm wavelength range at room temperature, and further predict a detection bandwidth of at least 47 MHz. Our demonstration lays the foundations for graphene high-speed mid-infrared technologies.
关键词： high-quality graphene,broad wavelength range,scattering channels,Mid-infrared bolometer,temperature coefficient of resistance
更新于2025-09-23 15:21:01
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Direct and Efficient Conversion from Low-Quality Graphite to High-Quality Graphene Nanoplatelets
摘要： Low-quality graphite (L-graphite), containing various impurities (e.g., metals and inorganics), can be directly and efficiently converted into high-quality iodine-doped graphene nanoplatelets (HIGnPs) via mechanochemical ball-milling in the presence of iodine (I2) with subsequent work-up procedures. Despite using L-graphite, the resultant HIGnPs show high-quality characteristics, including large specific surface area (969 m2 g?1), lower metallic residues, and well-maintained graphitic structure. In addition, HIGnPs display remarkable electrocatalytic performance for oxygen reduction reaction (ORR), involving benefits such as higher selectivity, longer-term stability, and better tolerance to methanol crossover/CO poisoning effects. Therefore, simple mechanochemical ball-milling in solid state can produce high-quality graphene nanoplatelets in large quantity at low-cost for commercialization, regardless of the initial quality of the graphite.
关键词： Oxygen reduction reaction,Mechanochemical reaction,High-quality graphene,ball-milling,Low-quality graphite
更新于2025-09-10 09:29:36