2.1 µm multi-quantum well laser epitaxially grown on on-axis (001) InP/SiO2/Si substrate fabricated by ion-slicing.

A cost-effective method to achieve a 2-3 µm wavelength light source on silicon represents a major challenge. In this study, we have developed a novel approach that combines an epitaxial growth and the ion-slicing technique. A 2.1 µm wavelength laser on a wafer-scale heterogeneous integrated InP/SiO2/Si (InPOI) substrate fabricated by ion-slicing technique was achieved by epitaxial growth. The performance of the lasers on the InPOI are comparable with the InP, where the threshold current density (Jth) was 1.3 kA/cm2 at 283 K when operated under continuous wave (CW) mode. The high thermal conductivity of Si resulted in improved high-temperature laser performance on the InPOI. The proposed method offers a novel means of integrating an on-chip light source.

2D Indium Phosphorus Sulfide (In2 P3 S9 ): An Emerging van der Waals High-k Dielectrics.

2D van der Waals (vdW) semiconductors hold great potentials for more-than-Moore field-effect transistors (FETs), and the efficient utilization of their theoretical performance requires compatible high-k dielectrics to guarantee the high gate coupling efficiency. The deposition of traditional high-k dielectric oxide films on 2D materials usually generates interface concerns, thereby causing the carrier scattering and degeneration of device performance. Here, utilizing a space-confined epitaxy growth approach, the authors successfully obtained air-stable ultrathin indium phosphorus sulfide (In2 P3 S9 ) nanosheets, the thickness of which can be scaled down to monolayer limit (≈0.69 nm) due to its layered structure. 2D In2 P3 S9 exhibits excellent insulating properties, with a high dielectric constant (≈24) and large breakdown voltage (≈8.1 MV cm-1 ) at room temperature. Serving as gate insulator, ultrathin In2 P3 S9 nanosheet can be integrated into MoS2 FETs with high-quality dielectric/semiconductor interface, thus providing a competitive electrical performance of device with subthreshold swings (SS) down to 88 mV dec-1 and a high ON/OFF ratio of 105 . This study proves an important strategy to prepare 2D vdW high-k dielectrics, and greatly facilitates the ongoing research of 2D materials for functional electronics.

Enhanced thermoelectric performance of CdO : Ag nanocomposites.

CdO : Ag nanocomposites with metallic Ag nanoparticles embedded in the polycrystalline CdO matrix were synthesized by the solid-state reaction method. The addition of Ag led to increased grain boundaries of CdO and created numerous CdO/Ag interfaces. By incorporating Ag into the CdO matrix, the power factor was increased which was probably due to the carrier energy filtering effect induced by the enhanced energy-dependent scattering of electrons. In addition, reduced thermal conductivity was also achieved by stronger phonon scattering from grain boundaries, CdO/Ag interfaces and Ag nanoparticles. These concomitant effects resulted in enhanced ZT values for all CdO : Ag nanocomposites, demonstrating that the strategy of introducing metallic Ag nanoparticles into the CdO host was very effective in optimizing the thermoelectric performance.