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This study employs first-principles calculations to investigate the behavior of two-dimensional carriers at the interfaces and surfaces of polar/polar LaAlO/KTaO (LAO/KTO) heterostructures. Unlike traditional LaAlO/SrTiO (LAO/STO) polar/nonpolar heterostructures with LaAlO unit-cell thickness-dependent critical conductive behavior, the LaAlO/KTaO heterostructures are demonstrated to have intrinsic two-dimensional carriers with carrier concentrations reaching up to 10 cm, significantly higher than those observed in LaAlO/SrTiO systems. Furthermore, in contrast to traditional sandwich heterostructure models, the single-interface LaAlO/KTaO heterostructures exhibit no bandgap dependence on the LaAlO thickness. These phenomena arise from the bipolar characteristics of the LaAlO/KTaO 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 LaAlO/KTaO heterostructures and provides potential strategies for manipulating these two-dimensional carriers in relevant materials and devices.
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http://dx.doi.org/10.1039/d5cp00734h | DOI Listing |
ACS Nano
September 2025
College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, China.
Polymorphic two-dimensional (2D) transition metal dichalcogenides (TMDCs) exhibit diverse properties for optoelectronic applications. Here, utilizing phase-engineered MoTe as a prototypical platform, we comprehensively explored its ultrafast and nonlinear optical properties to complete the fundamental framework of phase-dependent optical phenomena in 2D TMDCs. Starting with the phase-selective synthesis of 2H- and 1T'-MoTe with tailored thicknesses, we revealed their distinct photocarrier relaxation mechanisms using intensive power-/temperature-/thickness-dependent transient absorption spectra (TAS).
View Article and Find Full Text PDFJ Phys Chem Lett
September 2025
Hunan Key Laboratory of Nanophotonics and Devices, Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics, Central South University, Changsha, Hunan 410083, China.
The optoelectronic properties of perovskite/two-dimensional (2D) material van der Waals heterojunctions provide greater potential for innovative neuromorphic devices. However, the traditional growth of heterojunctions still relies on strict lattice matching and high-temperature processes, which hinder high-quality interface construction and efficient carrier transport. Here, the 2D CsPbI/MoS heterojunction is realized via the van der Waals epitaxy process, overcoming lattice matching limitations.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Guangxi Key Lab of Processing for Nonferrous Metals and Featured Materials and Key Lab of New Processing Technology for Nonferrous Metals and Materials, Ministry of Education, School of Resources, environments and Materials, Guangxi University, Nanning 530004, China.
To date, Cu(I)-based metal halides with high photoluminescence quantum yields (PLQYs) have primarily focused on their zero-dimensional or one-dimensional structures, significantly reflecting the charge or carrier localization. Designing two-dimensional (2D) hybrid copper(I) halides remains a significant challenge for optoelectronic applications, particularly in simultaneously achieving high PLQY and exceptional structural stability. Here, we report a novel series of 2D hybrid Cu(I) halides, (TDMP)CuX (TDMP = 2,5-dimethylpiperazine and X = Cl, Br), synthesized through simple solution-cooling crystallization methods.
View Article and Find Full Text PDFNanoscale
September 2025
School of Materials Science and Engineering, Beihang University, Beijing 100191, China.
The challenge of photocatalytic hydrogen production has motivated a targeted search for MXenes as a promising class of materials for this transformation because of their high mobility and high light absorption. High-throughput screening has been widely used to discover new materials, but the relatively high cost limits the chemical space for searching MXenes. We developed a deep-learning-enabled high-throughput screening approach that identified 14 stable candidates with suitable band alignment for water splitting from 23 857 MXenes.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen, Guangdong518055, China.
The rapid development of liquid exfoliation technology has boosted fundamental research and applications of ultrathin two-dimensional (2D) materials. However, the small-sized exfoliated 2D materials with a high specific surface area may exhibit poor chemical stability. Understanding the stability of 2D crystals will be significant for their preservation and service and for the development of new stable phases via the spontaneous transition from unstable structures.
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