当前位置: X-MOL 学术J. Phys. Chem. Lett. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Pressure-Regulated Dynamic Stereochemical Role of Lone-Pair Electrons in Layered Bi2O2S
The Journal of Physical Chemistry Letters ( IF 4.8 ) Pub Date : 2020-11-02 , DOI: 10.1021/acs.jpclett.0c02893
Kejun Bu 1 , Hui Luo 1 , Songhao Guo 1 , Mei Li 1 , Dong Wang 1 , Hongliang Dong 1 , Yang Ding 1 , Wenge Yang 1 , Xujie Lü 1
Affiliation  

Lone-pair electrons (LPEs) ns2 in subvalent 14 and 15 groups lead to highly anharmonic lattice and strong distortion polarization, which are responsible for the groups’ outstanding thermoelectric and optoelectronic properties. However, their dynamic stereochemical role in structural and physical properties is still unclear. Here, by introducing pressure to tune the behavior of LPEs, we systematically investigate the lone-pair stereochemical role in a Bi2O2S. The gradually suppressed LPEs during compression show a nonlinear repulsive electrostatic force, resulting in two anisotropic structural transitions. An orthorhombic-to-tetragonal phase transition happens at 6.4 GPa, caused by the dynamic cation centering. This structural transformation effectively modulates the optoelectronic properties. Further compression beyond 13.2 GPa induces a 2D-to-3D structural transition due to the disappearance of the Bi-6s2 LPEs. Therefore, the pressure-induced LPE reconfiguration dominates these anomalous variations of lattice, electronic, and optical properties. Our findings provide new insights into the materials optimization by regulating the characters of LPEs.

中文翻译:

层状Bi 2 O 2 S中孤对电子的压力调节动态立体化学作用

亚基14和15基团中的孤对电子(LPE)n s 2导致高度非谐晶格和强畸变极化,这是该基团出色的热电和光电特性的原因。然而,它们在结构和物理性质上的动态立体化学作用仍不清楚。在这里,通过引入压力来调节LPE的行为,我们系统地研究了Bi 2 O 2中的孤对立体化学作用。S.在压缩过程中逐渐被抑制的LPE显示出非线性排斥静电力,从而导致两个各向异性的结构转变。由动态阳离子对中引起的正交向四方相变发生在6.4 GPa。这种结构转换有效地调节了光电性能。由于Bi-6s 2 LPE的消失,超过13.2 GPa的进一步压缩会引起2D到3D的结构转变。因此,压力引起的LPE重新配置控制了晶格,电子和光学特性的这些异常变化。我们的发现通过调节LPE的特性,为材料优化提供了新的见解。
更新日期:2020-11-19
down
wechat
bug