Improving heat transfer in hybrid nano/microelectronic systems is a challenge, mainly due to the high thermal boundary resistance (TBR) across the interface. Herein, we focus on gallium nitride (GaN)/diamond interface-as a model system with various high power, high temperature, and optoelectronic applications-and perform extensive reverse nonequilibrium molecular dynamics simulations, decoding the interplay between the pillar length, size, shape, hierarchy, density, arrangement, system size, and the interfacial heat transfer mechanisms to substantially reduce TBR in GaN-on-diamond devices. We found that changing the conventional planar interface to nanoengineered, interlaced architecture with optimal geometry results in >80% reduction in TBR.
View Article and Find Full Text PDFHeteroatom-doped carbon dots (CDs), due to their excellent photoluminescence (PL) properties, attracted widespread attention recently and demonstrated immense promise for diverse applications, particularly for biological applications. The objective of this feature article is to provide a comprehensive overview of the recent progress in the research and development of heteroatom-doped CDs and a detailed description of the influence of single or co-doping heteroatoms on their PL behavior. The most recent understanding and critical insights into the PL mechanism of heteroatom-doped CDs are also highlighted.
View Article and Find Full Text PDFHeteroatom doped carbon dots (CDs), with high photoluminescence quantum yield (PLQY), are of keen interest in various applications such as chemical sensors, bio-imaging, electronics, and photovoltaics. Zinc, an important element assisting the electron-transfer process and an essential trace element for cells, is a promising metal dopant for CDs, which could potentially lead to multifunctional CDs. In this contribution, we report a single-step, high efficiency, hydrothermal method to synthesize Zn-doped carbon dots (Zn-CDs) with a superior PLQY.
View Article and Find Full Text PDFWith millions of years of natural evolution, organisms have achieved sophisticated structures, patterns or textures with complex, spontaneous multifunctionality. Among all the fascinating characteristics observed in biosystems, self-cleaning ability is regarded as one of the most interesting topics in biomimicry because of its potential applications in various fields such as aerospace, energy conversion and biomedical and environmental protection. Recently, in-depth studies have been carried out on various compelling biostructures including lotus leaves, shark skins, butterfly wings and gecko feet.
View Article and Find Full Text PDFAn in situ strategy for the preparation of graphene immobilized on sand using asphalt, a cheap carbon precursor is presented. The as-synthesized material was characterized in detail using various spectroscopic and microscopic techniques. The presence of G and D bands at 1578 cm(-1) and 1345 cm(-1) in Raman spectroscopy and the 2D sheet-like structure with wrinkles in transmission electron microscopy confirmed the formation of graphenic materials.
View Article and Find Full Text PDFThis paper describes a green method for the synthesis of graphenic material from cane sugar, a common disaccharide. A suitable methodology was introduced to immobilize this material on sand without the need of any binder, resulting in a composite, referred to as graphene sand composite (GSC). Raman spectroscopy confirmed that the material is indeed graphenic in nature, having G and D bands at 1597 and 1338 cm(-1), respectively.
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