Single lanthanide (Ln) ion doped upconversion nanoparticles (UCNPs) exhibit great potential for biomolecule sensing and counting. Plasmonic structures can improve the emission efficiency of single UCNPs by modulating the energy transferring process. Yet, achieving robust and large-area single UCNP emission modulation remains a challenge, which obstructs investigation and application of single UCNPs.
View Article and Find Full Text PDFTwo-dimensional (2D) ferroelectric field-effect transistors (Fe-FETs) have attracted extensive interest as a competitive platform for implementing future-generation functional electronics, including digital memory and brain-inspired computing circuits. In 2D Fe-FETs, the 2D ferroelectric materials are more suitable as gate dielectric materials compared to 3D ferroelectric materials. However, the current 2D ferroelectric materials (represented by α-InSe) need to be integrated with other 3D gate dielectric layers because of their high conductivity as a ferroelectric semiconductor.
View Article and Find Full Text PDFThe emerging data-intensive applications in optoelectronics are driving innovation toward the fused integration of sensing, memory, and computing to break through the restrictions of the von Neumann architecture. However, the present photodetectors with only optoelectronic conversion functions cannot satisfy the growing demands of the multifunctions required in single devices. Here, a novel route for the integration of non-volatile memory into a photodetector is proposed, with a WSe /h-BN van der Waals heterostructure on a Si/SiO substrate to realize in-memory photodetection.
View Article and Find Full Text PDFTwo-dimensional (2D) materials have been demonstrated to be promising candidates to design high performance photodetectors owing to their strong light-matter interaction. However, the performance of 2D material photodetectors is still unsatisfactory, such as slow response speed due to defects and vulnerable contact interface, which impede their rapid development in the field of optoelectronics. In this paper, we obtained the ideal and large photosensitive van der Waals Schottky interface by the laminating-flipping method.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2019
Transition metal dichalcogenides (TMDs) are a category of promising two-dimensional (2D) materials for the optoelectronic devices, and their unique characteristics include tunable band gap, nondangling bonds as well as compatibility to large-scale fabrication, for instance, chemical vapor deposition (CVD). MoS is one of the first TMDs that is well studied in the photodetection area widely. However, the low photoresponse restricts its applications in photodetectors unless the device is applied with ultrahigh source-drain voltage ( V) and gate voltage ( V).
View Article and Find Full Text PDFThis paper addresses two questions concerning the relationship between state policies and environmental transformation in China in the past four decades. The first one deals with the promotion of agricultural productivity since the 1980s; the second, the water conservation measures as a response to the water crisis that peaked in the early 2000s. We had chosen Minqin County in northwestern China, one of the most fragile arid oasis systems in the world, as the study area.
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