Strategic improvement of second and third harmonic generation in multifunctional Cu-Sn-S3 ternary semiconducting thin films

Ordering in ternary nitride semiconducting alloys

We present a thorough theoretical study of ordering phenomena in nitride ternary alloys GaInN, AlInN, and AlGaN. Using the Monte Carlo approach and energetics based on the Keating model we analyze the influence of various factors on ordering in bulk crystals and epitaxial layers. We characterize the degree of both short range order (SRO) and long ranger order (LRO) for different compositions, temperatures and for substrates associated with different epitaxial strain. For the description of the SRO the Warren-Cowley parameters related to the first four coordination shells are used. The LRO is d…

Triggering superconductivity, semiconducting states, and ternary valley structure in graphene via functionalization with Si-N layers

Opening a band gap and realizing static valley control have been long sought after in graphenebased two-dimensional (2D) materials. Motivated by the recent success in synthesizing 2D materials passivated by Si-N layers, here, we propose two new graphene-based materials, 2D C2SiN and CSiN, via first-principles calculations. Monolayer C2SiN is metallic and realizes superconductivity at low temperatures. Monolayer CSiN enjoys excellent stability and mechanical property. It is a semiconductor with a ternary valley structure for electron carriers. Distinct from existing valleytronic platforms, thes…

Tunable Multifunctional Topological Insulators in Ternary Heusler Compounds

Recently the Quantum Spin Hall effect (QSH) was theoretically predicted and experimentally realized in a quantum wells based on binary semiconductor HgTe[1-3]. QSH state and topological insulators are the new states of quantum matter interesting both for fundamental condensed matter physics and material science[1-11]. Many of Heusler compounds with C1b structure are ternary semiconductors which are structurally and electronically related to the binary semiconductors. The diversity of Heusler materials opens wide possibilities for tuning the band gap and setting the desired band inversion by ch…

In2Se3铁电半导体场效应晶体管中场致可逆相变与负微分电阻

Field-induced reversible phase transition and negative differential resistance in In2Se3 ferroelectric semiconducting FETs

本研究通过实验证明In2Se3铁电半导体场效应晶体管中栅极可调负微分电阻源于场致可逆相变，并揭示面内电场驱动层间滑动与应力诱导相变机制，为多功能纳米电子学提供新思路。

Two-Dimensional Semiconducting Metal Organic Frameworks with Auxetic Effect, Room Temperature Ferrimagnetism, Chiral Ferroelectricity, Bipolar Spin Polarization and Topological Nodal Lines/Points

Two-dimensional (2D) semiconductors integrated with two or more functions are the cornerstone for constructing multifunctional nanodevices, but remain largely limited. Here, by tuning the spin state of organic linkers and the symmetry/topology of crystal lattice, we predict a class of unprecedented multifunctional semiconductors in 2D Cr(II) five-membered heterocyclic metal organic frameworks that simultaneously possess auxetic effect, room temperature ferrimagnetism, chiral ferroe-lectricity, electrically reversible spin polarization and topological nodal lines/points. Taking 2D Cr(TDZ)$_2$ (…

Novel Multifunctional Materials Based on Oxide Thin Films and Artificial Heteroepitaxial Multilayers

Transition metal oxides show fascinating physical properties such as high temperature superconductivity, ferro- and antiferromagnetism, ferroelectricity or even multiferroicity. The enormous progress in oxide thin film technology allows us to integrate these materials with semiconducting, normal conducting, dielectric or non-linear optical oxides in complex oxide heterostructures, providing the basis for novel multi-functional materials and various device applications. Here, we report on the combination of ferromagnetic, semiconducting, metallic, and dielectric materials properties in thin fil…