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Laser‐Guided Microcanvas Printing of Multicolor Upconversion Nanoparticles on Molybdenum Disulfide Monolayer
| Content Provider | Semantic Scholar |
|---|---|
| Author | Liu, Xiaogang Sow, Chorng Haur |
| Copyright Year | 2019 |
| Abstract | DOI: 10.1002/admi.201901673 ablation techniques,[1,2] to microwriting of photoresist patterns in conventional lithography,[3–6] lasers have played critical roles in driving local self-assemblies or chemical changes to produce desired micropatterns. Beyond these traditional techniques, focused laser beams coupled to low-cost microscopes have also been exploited for spatially directed, site-specific oxidation of various nanomaterials, as well as in situ production of a diverse range of nanostructures on photoactive substrates. Through a laser path directed into a metallurgical microscope, the setup produces laser writing systems flexible to accommodate variations in the laser excitation wavelength and the nature of the substrate materials. Furthermore, the avoidance of substrate pretreatment, mask alignment, and potential chemical contamination ascends the technique of direct laser writing in favor of conventional lithographic methods. In the most fundamental operation of the direct laser writing technique, the focused laser beam incident on the sample provides sufficient thermal or photonic energy for the material to overcome the activation barrier and partake in site-specific local chemical changes. The first generation works demonstrated the capability for spatially refined removal of materials for patterning and crafting functional microstructures. These efforts include laser pruning of carbon nanotube arrays to produce 2D/3D microstructures[7] and high-efficiency quantum dot (QD) nanosieves,[8] laser vaporization of highly inert crosslinked SU-8 epoxies,[9] and localized combustion of porphyrin nanotubes (PNTs).[10] Beyond that, subsequent studies were tuned toward laser stimulated oxidation of various nanomaterials, including GeSe2 nanostructures,[11] mesoporous silicon nanowires (mp-SiNWs),[12] CdSxSe1-x nanobelts,[13] and phosphorene nanofilms.[14,15] These works not only explored the rich chemistry and physics at play on the local scale, but also resulted in the formation of highly functional photodetectors and chemical sensors. On 2D materials, the laser was found to affect these photoactive thin layers differently, providing controlled alterations to the inherently unique optical and chemical natures of the layer surfaces.[16] More importantly, the laser-induced chemical change could produce regional catalytic microsites capable of subsequent reduction of Au3+ ions to Au nanoparticles Scanning focused laser beams incident on nanomaterials have provided a nondestructive and facile technique to fabricate micropatterns of a wide variety of hybrid materials. Conventionally, the technique is limited to localized chemical modification or in situ reduction of specific metal ions en route to heterogeneous material systems. However, as hybrid structures continue to be an essential form to couple various material properties and bring forth nanostructures with designable traits, the need for a flexible technique to interface nanomaterials presynthesized in higher quality remains an important challenge. Herein, a technique for laser-guided microcanvas formation by anchoring preformed upconversion nanoparticles at specific sites on a MoS2 monolayer surface is presented. The technique expands the building blocks in laser-produced hybrid structures to include presynthesized nanomaterials. The upconversion microstructures are formed via a microbubble-assisted mechanism, with distinct emission contrast against the background. The proof-of-concept production of a multicolor upconversion microcanvas marks the potential for full-color high-resolution displays while the technique opens up the possibility of fabricating an expandable range of new hybrid structures. |
| Starting Page | 1901673 |
| Ending Page | 1901673 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| DOI | 10.1002/admi.201901673 |
| Volume Number | 6 |
| Alternate Webpage(s) | https://cpb-us-w2.wpmucdn.com/blog.nus.edu.sg/dist/0/6982/files/2019/12/146.pdf |
| Alternate Webpage(s) | https://doi.org/10.1002/admi.201901673 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
