Revealing the Role of the Tetragonal Distortion in the Metal-Insulator Transition of Co- and Fe-Doped NiS.

Although the NiS exhibits the most widely adjustable metal-to-insulator (MIT) properties among the chalcogenides, the mechanisms, with respect to the regulations in their critical temperatures (), are yet unclear. Herein, we demonstrate the overlooked role associated with the structurally tetragonal distortion in elevating the of NiS; this is in distinct contrast to the previously expected hybridization and bandwidth regulations that usually reduces . Compared to the perspective of structure distortions, the orbital hybridization and band regulation of NiS are ∼19 times more effective adjustment in .

Manipulating the metal-to-insulator transitions of VO by combining compositing and doping strategies.

Vanadium dioxide (VO) exhibits the most abrupt metal-to-insulator transition (MIT) property near room temperature among the representative 3d-orbital correlated oxides, and its structural variation during the MIT usually results in poor mechanical properties as bulk pellets. Moreover, compositing with highly resistive oxides has been reported to improve the mechanical strength of bulk VO since the generation and propagation of microcracks is suppressed upon thermocycling across the MIT; further, their respective impacts on electrical transportation are yet unclear. Herein, we demonstrate the role of these highly resistive oxide composites (, HfO, CoO and AlO) in reducing charge leakage along the microcracks within the insulating phase of VO, leading to more abrupt MIT properties from the perspective of electrical transportation.

Revealing the Role of Hydrogen in Electron-Doping Mottronics for Strongly Correlated Vanadium Dioxide.

Hydrogen-associated electron-doping Mottronics for d-band correlated oxides (e.g., VO) opens up a new paradigm to regulate the electronic functionality via directly manipulating the orbital configuration and occupancy.

Revealing the role of interfacial heterogeneous nucleation in the metastable thin film growth of rare-earth nickelate electronic transition materials.

Although rare-earth nickelates (ReNiO, Re ≠ La) exhibit abundant electronic phases and widely adjustable metal to insulator electronic transition properties, their practical electronic applications are largely impeded by their intrinsic meta-stability. Apart from elevating the oxygen reaction pressure, heterogeneous nucleation is expected to be an alternative strategy that enables the crystallization of ReNiO at low meta-stability. In this work, the respective roles of high oxygen pressure and heterogeneous interface in triggering ReNiO thin film growth in the metastable state are revealed.

Electron-Doping Mottronics in Strongly Correlated Perovskite.

The discovery of hydrogen-induced electron localization and highly insulating states in d-band electron correlated perovskites has opened a new paradigm for exploring novel electronic phases of condensed matters and applications in emerging field-controlled electronic devices (e.g., Mottronics).

A d-Band Electron Correlated Thermoelectric Thermistor Established in Metastable Perovskite Family of Rare-Earth Nickelates.

The d-band electron correlations shed a light on bridging multiple functionalities within one material system, and this further extends the horizon in material designs and their emerging device applications. Herein, we demonstrate the combination of thermoelectric and thermistor functionalities within the perovskite family of correlated rare-earth nickelates (NiO) having small rare-earth elements (i.e.

Enhancing the Photocurrent of Top-Cell by Ellipsoidal Silver Nanoparticles: Towards Current-Matched GaInP/GaInAs/Ge Triple-Junction Solar Cells.

A way to increase the photocurrent of top-cell is crucial for current-matched and highly-efficient GaInP/GaInAs/Ge triple-junction solar cells. Herein, we demonstrate that ellipsoidal silver nanoparticles (Ag NPs) with better extinction performance and lower fabrication temperature can enhance the light harvest of GaInP/GaInAs/Ge solar cells compared with that of spherical Ag NPs. In this method, appropriate thermal treatment parameters for Ag NPs without inducing the dopant diffusion of the tunnel-junction plays a decisive role.

Direct tuning of electrical properties in nano-structured Bi2Se0.3Te2.7 by reversible electrochemical lithium reactions.

Lithium intercalation and de-intercalation processes have been used to fabricate bulk Bi(2)Se(0.3)Te(2.7) with internal nanostructures.

Top-down fabrication of nano-scaled Bi2Se(0.3)Te(2.7) associated by electrochemical Li intercalation.

A convenient top-down method for preparation of Bi(2)Se(0.3)Te(2.7) crystalline nano-particles has been demonstrated.