Kristoffer Eggestad, Benjamin A D Williamson, Dennis Meier, Sverre M Selbach
{"title":"Mobile intrinsic point defects for conductive neutral domain walls in LiNbO<sub>3</sub>.","authors":"Kristoffer Eggestad, Benjamin A D Williamson, Dennis Meier, Sverre M Selbach","doi":"10.1039/d4tc02856b","DOIUrl":null,"url":null,"abstract":"<p><p>Conductive ferroelectric domain walls (DWs) hold great promise for neuromorphic nanoelectronics as they can contribute to realize multi-level diodes and nanoscale memristors. Point defects accumulating at DWs will change the local electrical transport properties. Hence, local, inter-switchable n- and p-type conductivity at DWs can be achieved through point defect population control. Here, we study the impact of point defects on the electronic structure at neutral domain walls in LiNbO<sub>3</sub> by density functional theory (DFT). Segregation of Li and O vacancies was found to be energetically favourable at neutral DWs, implying that charge-compensating electrons or holes can give rise to n- or p-type conductivity. Changes in the electronic band gap and defect transition levels are discussed with respect to local property engineering, opening the pathway for reversible tuning between n- and p-type conduction at neutral ferroelectric DWs. Specifically, the high Curie temperature of LiNbO<sub>3</sub> and the significant calculated mobility of O and Li vacancies suggest that thermal annealing and applied electric fields can be used experimentally to control point defect populations, and thus enable rewritable pn-junctions.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":null,"pages":null},"PeriodicalIF":5.7000,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11414182/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Materials Chemistry C","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1039/d4tc02856b","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Conductive ferroelectric domain walls (DWs) hold great promise for neuromorphic nanoelectronics as they can contribute to realize multi-level diodes and nanoscale memristors. Point defects accumulating at DWs will change the local electrical transport properties. Hence, local, inter-switchable n- and p-type conductivity at DWs can be achieved through point defect population control. Here, we study the impact of point defects on the electronic structure at neutral domain walls in LiNbO3 by density functional theory (DFT). Segregation of Li and O vacancies was found to be energetically favourable at neutral DWs, implying that charge-compensating electrons or holes can give rise to n- or p-type conductivity. Changes in the electronic band gap and defect transition levels are discussed with respect to local property engineering, opening the pathway for reversible tuning between n- and p-type conduction at neutral ferroelectric DWs. Specifically, the high Curie temperature of LiNbO3 and the significant calculated mobility of O and Li vacancies suggest that thermal annealing and applied electric fields can be used experimentally to control point defect populations, and thus enable rewritable pn-junctions.
导电铁电畴壁(DWs)在神经形态纳米电子学中大有可为,因为它们有助于实现多级二极管和纳米级忆阻器。积聚在畴壁上的点缺陷会改变局部的电传输特性。因此,可以通过控制点缺陷群来实现 DW 的局部、可相互切换的 n 型和 p 型导电性。在此,我们通过密度泛函理论(DFT)研究了点缺陷对 LiNbO3 中性畴壁电子结构的影响。研究发现,在中性畴壁上,Li 和 O 空位的分离在能量上是有利的,这意味着电荷补偿电子或空穴可以产生 n 型或 p 型导电性。讨论了电子带隙和缺陷转变水平的变化与局部特性工程的关系,为中性铁电 DW 的 n 型和 p 型传导之间的可逆调整开辟了道路。具体来说,LiNbO3 的高居里温度以及计算得出的 O 和 Li 空位的显著迁移率表明,热退火和外加电场可用于实验控制点缺陷群,从而实现可重写的 pn 结。
期刊介绍:
The Journal of Materials Chemistry is divided into three distinct sections, A, B, and C, each catering to specific applications of the materials under study:
Journal of Materials Chemistry A focuses primarily on materials intended for applications in energy and sustainability.
Journal of Materials Chemistry B specializes in materials designed for applications in biology and medicine.
Journal of Materials Chemistry C is dedicated to materials suitable for applications in optical, magnetic, and electronic devices.
Example topic areas within the scope of Journal of Materials Chemistry C are listed below. This list is neither exhaustive nor exclusive.
Bioelectronics
Conductors
Detectors
Dielectrics
Displays
Ferroelectrics
Lasers
LEDs
Lighting
Liquid crystals
Memory
Metamaterials
Multiferroics
Photonics
Photovoltaics
Semiconductors
Sensors
Single molecule conductors
Spintronics
Superconductors
Thermoelectrics
Topological insulators
Transistors