Electrochemical doping of few-layer ZrNCl from first principles: Electronic and structural properties in field-effect configuration
Electrochemical doping of few-layer ZrNCl from first principles: Electronic and structural properties in field-effect configuration
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DOI：
10.1103/physrevb.89.245406
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发表时间：
2014-06-06
影响因子：
3.7
通讯作者：
Mauri, Francesco
中科院分区：
文献类型：
--
作者：
Brumme, Thomas;Calandra, Matteo;Mauri, Francesco
我们发展了场效应器件掺杂的第一性原理理论方法。该方法不仅可以计算电子结构，还可以利用密度泛函理论在场效应组态中实现结构的完全驰豫。我们将我们的方法应用于离子液体基单分子层、双分子层和三层分子膜的场效应掺杂，详细分析了电场引起的结构变化。我们发现，与以前的实验工作相反，只有一层ZrNCl层是电化学掺杂的，这导致了层内结构的巨大变化。令人惊讶的是，尽管有这些结构和电子的变化，费米能级的态密度与掺杂无关。我们的发现意味着对电化学掺杂的ZrNCl相图进行了实质性的修正，并阐明了与Li嵌入的块体ZrNCl的超导电性的重要区别。
We develop a first-principles theoretical approach to doping in field-effect devices. The method allows for calculation of the electronic structure as well as complete structural relaxation in field-effect configuration using density-functional theory. We apply our approach to ionic-liquid-based field-effect doping of monolayer, bilayer, and trilayer ZrNCl and analyze in detail the structural changes induced by the electric field. We show that, contrary to what is assumed in previous experimental works, only one ZrNCl layer is electrochemically doped and that this induces large structural changes within the layer. Surprisingly, despite these structural and electronic changes, the density of states at the Fermi energy is independent of the doping. Our findings imply a substantial revision of the phase diagram of electrochemically doped ZrNCl and elucidate crucial differences with superconductivity in Li-intercalated bulk ZrNCl.