Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Kentucky

Theses/Dissertations

Ac-calorimetry

Articles 1 - 2 of 2

Full-Text Articles in Physics

Thermal Conductivities Of Organic Semiconductors, Yulong Yao Jan 2017

Thermal Conductivities Of Organic Semiconductors, Yulong Yao

Theses and Dissertations--Physics and Astronomy

Organic semiconductors have gained a lot of interest due to their ease of processing, low-cost and inherent mechanical flexibility. Although most of the research has been on their electronic and optical properties, knowledge of the thermal properties is important in the design of electronic devices as well. Our group has used ac-calorimetric techniques to measure both in-plane and transverse thermal conductivities of a variety of organic semiconductors including small-molecule crystals and polymer blends. For layered crystals composed of molecules with planar backbones and silylethynyl (or germylethynyl) sidegroups projecting between the layers, very high interplanar thermal conductivities have been observed, presumably …


The Development And Implementation Of Systems To Study The Physical Properites Of Tantalum Trisulfide And Small-Molecule Organic Semiconductors, Hao Zhang Jan 2015

The Development And Implementation Of Systems To Study The Physical Properites Of Tantalum Trisulfide And Small-Molecule Organic Semiconductors, Hao Zhang

Theses and Dissertations--Physics and Astronomy

The charge-density-wave (CDW) material orthorhombic tantalum trisulfide (TaS3) is a quasi-one dimensional material that forms long ribbon shaped crystals, and exhibits unique physical behavior. We have measured the dependence of the hysteretic voltage-induced torsional strain (VITS) in TaS3, which was first discovered by Pokrovskii et. al. in 2007, on temperature and applied torque. Our experimental results shows that the application of torque to the crystal could also change the VITS time constant, magnitude, and sign. This suggests that the VITS is a consequence of residual torsional strain originally present in the sample which twists the polarizations …