Nature 速递

2020_Nature_Gram-scale bottom-up flash graphene synthesis

• 拟解决科学问题：石墨烯制备

1. 自上而下：物理法 超声需大量溶剂和能量

2. 自上而下：化学法 需苛刻的氧化剂并在随后的还原中留下缺陷

3. 自下而上: 高质量(化学气相沉积或有机合成) 但是产量小

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

• 材料方法原理及创新点:

1. 用廉价的碳源甚至废弃的食物,

2. 快速焦耳热,可在1秒内得到

3. 克级别的石墨烯,具有涡轮状排序，

4. 无需溶剂和炉子，

5. 产率根据碳源变化，可高达90%，

6. 并且具有高纯度,无需纯化

7. 低缺陷

8. 低能耗

2020_Nature_Transparent ferroelectric crystals with ultrahigh piezoelectricity

• 拟解决科学问题：

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.

• 材料方法原理及创新点：

1. 利用交流电场调制畴结构原来不透明的PMN-PT,
2. 得到透明性赫尔高D33 2100 pC/N
3. 机电耦合系数K33 94%
4. 光电系数 220 Pc/V
5. 大筹结构也可实现高D33，颠覆传统

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

• 拟解决科学问题

wrinkles invariably form during CVD growth because of the strong coupling to the substrate, and these limit the large-scale homogeneity of the film

• 材料方法原理及创新点：

质子辅助气相沉积制备石墨烯，可以在基底上超平铺展，形成氢键，减少褶皱，减小范德华力，形成V型狄拉克锥电子能带结构，在原子面及深处

2020_Nature_Strain engineering and epitaxial stabilization of halide perovskites

閱讀更多 科研學術 的文章

關鍵字: 国创上头条 物理 速递