The two-dimensional n/p type carriers at the interface of LaAlO3/KTaO3 heterostructures

IF 2.9 3区化学 Q3 CHEMISTRY, PHYSICAL

Physical Chemistry Chemical Physics Pub Date : 2025-04-24 DOI:10.1039/d5cp00734h

Yirong Geng, Zuhui Hu, Chang Liu, Ruiling Gao, Hui Zhang, Le Fang, Wei Ren

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引用次数: 0

Abstract

This study employs first-principles calculations to investigate the behavior of two-dimensional carriers at the interfaces and surfaces of polar/polar LaAlO3/KTaO3 (LAO/KTO) heterostructures. Unlike the traditional LaAlO3/SrTiO3 (LAO/STO) polar/nonpolar heterostructures with LaAlO3 unit-cell thickness-dependent critical conductive behavior, the LaAlO3/KTaO3 heterostructures are demonstrated to have intrinsic two-dimensional carriers with carrier concentrations reaching up to 1014 cm-2, significantly higher than those observed in LaAlO3/SrTiO3 systems. Furthermore, in contrast to traditional sandwich heterostructure models, the single-interface LaAlO3/KTaO3 heterostructures exhibit no bandgap dependence on the LaAlO3 thickness. These phenomena arise from the bipolar characteristics of the LaAlO3/KTaO3 system, and it can introduce increased carrier density and reduce symmetry within the single-interface polar heterostructure. Simulation results also show that applying in-plane strain can suppress and even reverse the n/p-type of two-dimensional carriers at the interfaces. Additionally, the presence of oxygen vacancies enhances carrier accumulation by redistributing the internal polarization field of the heterostructures. Overall, this research offers a comprehensive elucidation of the behaviors and formation mechanisms for n/p-type two-dimensional carriers in polar/polar LaAlO3/KTaO3 heterostructures and provides potential strategies for manipulating these two-dimensional carriers in relevant materials and devices

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LaAlO3/KTaO3 异质结构界面上的二维 n/p 型载流子

本研究采用第一性原理计算研究了二维载流子在极性/极性LaAlO3/KTaO3 （LAO/KTO）异质结构界面和表面的行为。与传统LaAlO3/SrTiO3 （LAO/STO）极性/非极性异质结构不同，LaAlO3/KTaO3异质结构具有LaAlO3单胞厚度依赖的临界导电性，其载流子浓度可达1014 cm-2，显著高于LaAlO3/SrTiO3体系。此外，与传统的夹层异质结构模型相比，单界面LaAlO3/KTaO3异质结构的带隙与LaAlO3厚度无关。这些现象是由LaAlO3/KTaO3体系的双极性特性引起的，它会增加载流子密度，降低单界面极性异质结构内的对称性。模拟结果还表明，施加面内应变可以抑制甚至逆转界面处二维载流子的n/p型。此外，氧空位的存在通过重新分配异质结构的内部极化场来促进载流子的积累。总的来说，本研究全面阐明了极性/极性LaAlO3/KTaO3异质结构中n/p型二维载流子的行为和形成机制，并为在相关材料和器件中操纵这些二维载流子提供了潜在的策略

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Physical Chemistry Chemical Physics 化学-物理：原子、分子和化学物理

CiteScore

5.50

自引率

9.10%

发文量

2675

审稿时长

2.0 months

期刊介绍： Physical Chemistry Chemical Physics (PCCP) is an international journal co-owned by 19 physical chemistry and physics societies from around the world. This journal publishes original, cutting-edge research in physical chemistry, chemical physics and biophysical chemistry. To be suitable for publication in PCCP, articles must include significant innovation and/or insight into physical chemistry; this is the most important criterion that reviewers and Editors will judge against when evaluating submissions. The journal has a broad scope and welcomes contributions spanning experiment, theory, computation and data science. Topical coverage includes spectroscopy, dynamics, kinetics, statistical mechanics, thermodynamics, electrochemistry, catalysis, surface science, quantum mechanics, quantum computing and machine learning. Interdisciplinary research areas such as polymers and soft matter, materials, nanoscience, energy, surfaces/interfaces, and biophysical chemistry are welcomed if they demonstrate significant innovation and/or insight into physical chemistry. Joined experimental/theoretical studies are particularly appreciated when complementary and based on up-to-date approaches.