Picosecond optical pulse sources1 have been playing an increasingly impor tant role in the study of ultrafast processes and have potential application to highspeed electronics2 and optical communications. Interest in picosecond techniques has recently been stimulated by the generation of ultrashort pulses at high repetition rate, 3 but conventional sources have remained large and cumbersome lab...

characteristics at 20°C. The threshold current (density) is 57mA (-3.2kA/cm2), which is as low as that for a 650nmband laser diode with a double-heterostructure (DH structure) [l]. We believe this to be the lowest ever value for a 630nmband AlGaInP laser diode. The maximum CW output power is -15mW, and this is limited by the C O D (catastrophic optical damage) of this structure. The slope effic...

Thin-body p-channel MOS transistors with a SiGe/Si heterostructure channel were fabricated on silicon-on-insulator (SOI) substrates. A novel lateral solid-phase epitaxy process was employed to form the thin-body for the suppression of shortchannel effects. A selective silicon implant that breaks up the interfacial oxide was shown to facilitate unilateral crystallization to form a single crystal...

Single layer graphene is an ideal material for the base layer of hot electron transistors (HETs) for potential terahertz (THz) applications. The ultrathin body and exceptionally long mean free path maximizes the probability for ballistic transport across the base of the HET. We demonstrate for the first time the operation of a high-performance HET using a graphene/WSe2 van der Waals (vdW) heter...

The integration of magnetic material with semiconductors has been fertile ground for fundamental science as well as of great practical interest toward the seamless integration of information processing and storage. We create van der Waals heterostructures formed by an ultrathin ferromagnetic semiconductor CrI3 and a monolayer of WSe2. We observe unprecedented control of the spin and valley pseu...

Using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS), we examine the electronic structure of transition metal dichalcogenide heterostructures (TMDCHs) composed of monolayers of MoS2 and WS2. STS data are obtained for heterostructures of varying stacking configuration as well as the individual monolayers. Analysis of the tunneling spectra includes the influence of ...

P-channel GaN Metal Oxide Semiconductor Heterostructure Field Effect Transistors (MOSHFETs) utilising a polarization induced two Dimensional Hole Gas (2DHG) operate inherently in depletion mode (D-mode). The condition for their conversion to E-mode operation is examined via analytical expressions for the threshold voltage and verified via TCAD simulations. Between the two heterostructures (i) c...

In this paper, we fabricated p-Co₃O₄/n-TiO₂ heterostructures and investigated their gas sensing properties. The structural and morphological characterization were performed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy analysis (XPS). The electrical properties of the heterostructure were studied within the temperature range from 293 K to 42...

An electric field tunable magnetic hysteresis loop was studied in a multiferroic heterostructure consisting of a 25μm thick Metglas® ribbon affixed to a lead magnesium niobate–lead titanate (PMN–PT) crystal. This multiferroic heterostructure exhibits a considerably strong converse magnetoelectric effect, CME = −80%, where CME = [M(E)−M(0)]/M(0), and a converse magnetoelectric coupling constant,...

By tracking the delocalized states of the two-dimensional hole gas in a p-type GaAs/AlGaAs heterostructure as a function of magnetic field, we mapped out a phase diagram in the density magnetic field plane. We found that the energy of the delocalized state from the lowest Landau level flattens out as the magnetic field tends toward zero. This finding is different from that for the two-dimension...