The article overviews experimental results obtained by applying internal photoemission (IPE) spectroscopy methods to characterize electron states in single- or few-monolayer thick two-dimensional materials and at their interfaces. Several conducting (graphene) and semiconducting (transitional metal dichalcogenides MoS2, WS2, MoSe2, and WSe2) films ...
Published in Nano letters
Nanowires bring new possibilities to the field of hot-carrier photovoltaics by providing flexibility in combining materials for band engineering and using nanophotonic effects to control light absorption. Previously, an open-circuit voltage beyond the Shockley-Queisser limit was demonstrated in hot-carrier devices based on InAs-InP-InAs nanowire he...
status: published
Using internal photoemission of electrons from few-monolayer thin MoS2 films into SiO2 we found that the MoS2 layer transfer processing perturbs electroneutrality of the interface, leading to an increase of the electron barrier height by ≈0.5-1 eV as compared to the case of the same films synthesized directly on SiO2. This effect is associated with...
This paper presents the design, fabrication, and characterization of Schottky erbium/silicon photodetectors working at 1.55 µ / m. These erbium/silicon junctions are carefully characterized using both electric and optical measurements at room temperature. A Schottky barrier &Phi / B of ~673 meV is extrapolated / the photodetectors show externa...
Published in Nano letters
We report the systematic experimental studies demonstrating that a graphene layer inserted at metal/n-Si(001) interface is efficient to explore interface Fermi-level pinning effect. It is confirmed that an inserted graphene layer prevents atomic interdiffusion to form an atomically abrupt Schottky contact. The Schottky barriers of metal/graphene/n-...
Published in Journal of Electronic Materials
The band offset at the interface of a heterojunction is one of the most important parameters determining the characteristics of devices constructed from heterojunction. Accurate knowledge of band offsets and their temperature dependence will allow one to simulate and predict the device performances. We present a temperature-dependent internal-photo...
Extended electron states in insulating oxide layers on Si and high-mobility semiconductors The electron energy band spectrum is of prime importance when attempting to engineer insulating stacks for application in metal-oxide semiconductor structures for practical applications. In particular, transition from traditional silicon to semiconductors wit...
Thanks to its good thermal stability, including resistance to oxidation, platinum (Pt) is widely used in prototyping a wide spectrum of electron devices ranging from metaloxide- semiconductor (MOS) transistors to resistive switching memory cells. In this work, the energy barriers for electrons between the Fermi level of Pt and the conduction band o...
Published in Internal Photoemission Spectroscopy
