2020_Nature_Gram-scale bottom-up flash graphene synthesis
擬解決科學問題:石墨烯製備1. 自上而下:物理法 超聲需大量溶劑和能量
2. 自上而下:化學法 需苛刻的氧化劑並在隨後的還原中留下缺陷
3. 自下而上: 高質量(化學氣相沉積或有機合成) 但是產量小
Bottom-up synthesis of high-quality graphene is often restricted to ultrasmall amounts if performed by chemical vapour deposition or advanced synthetic organic methods, or it provides a defect-ridden structure if carried out in bulk solution
材料方法原理及創新點:1. 用廉價的碳源甚至廢棄的食物,
2. 快速焦耳熱,可在1秒內得到
3. 克級別的石墨烯,具有渦輪狀排序,
4. 無需溶劑和爐子,
5. 產率根據碳源變化,可高達90%,
6. 並且具有高純度,無需純化
7. 低缺陷
8. 低能耗
2020_Nature_Transparent ferroelectric crystals with ultrahigh piezoelectricity
擬解決科學問題:it is challenging to achieve high piezoelectricity and perfect transparency simultaneously because most high-performance piezoelectrics are ferroelectrics that contain high-density light-scattering domain walls.
材料方法原理及創新點:利用交流電場調製疇結構原來不透明的PMN-PT,得到透明性赫爾高D33 2100 pC/N 機電耦合係數K33 94%光電係數 220 Pc/V大籌結構也可實現高D33,顛覆傳統We find that increasing the domain size leads to a higher d33 value for the [001]-oriented rhombohedral PMN-PT crystals, challenging the conventional wisdom that decreasing the domain size always results in higher piezoelectricity
2020_Nature_Proton-assisted growth of ultra-flat graphene films
擬解決科學問題wrinkles invariably form during CVD growth because of the strong coupling to the substrate, and these limit the large-scale homogeneity of the film
材料方法原理及創新點:質子輔助氣相沉積製備石墨烯,可以在基底上超平鋪展,形成氫鍵,減少褶皺,減小范德華力,形成V型狄拉克錐電子能帶結構,在原子面及深處
2020_Nature_Strain engineering and epitaxial stabilization of halide perovskites