Growth and characterization of TbAs films

Abstract

We report on the molecular beam epitaxy growth and characterization of TbAs films. In situ reflection high energy electron diffraction and ex situ high resolution X-ray diffraction, reciprocal space mapping, and both scanning and transmission electron microscopy are used to confirm the complete film growth and study the films' morphology. Spectrophotometry measurements provide the energy of optical transitions, revealing a red shift in optical band gap with increasing thickness. The Hall effect measurements show temperature insensitive carrier concentrations, resistivities, and mobilities. The carrier concentration decreases and resistivity increases with increasing film thickness; mobility appears thickness independent. The films' reflectivity, obtained via Fourier transform infrared spectroscopy, shows a possible Drude edge that differs from the trend of other lanthanide monopnictides. These measurements show that TbAs is a degenerately doped semiconductor with a combination of electronic and optical properties that is dissimilar to other lanthanide monopnictides.

Effects of Co-Solvents on the Performance of PEDOT:PSS Films and Hybrid Photovoltaic Devices

“…Double-side polished intrinsic silicon wafers were used as substrates for the PEDOT:PSS conductivity measurements. Conductivity measurements were carried out by the van der Pauw technique on a custom built room temperature resistivity and Hall Effect system [11]. The resistivity of the films was measured twice (bi-directional by switching the four contacts between voltage and current probes) and the resulting values were averaged.…”

Hybrid functional calculations of electronic structure and carrier densities in rare-earth monopnictides

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Controlling magnetoresistance by tuning semimetallicity through dimensional confinement and heteroepitaxy

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