Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet succes...

Thermoelectric (TE) materials have undergone revolutionary progress over the last 20 years. The thermoelectric figure of merit ZT, which quantifies the ability of a material to convert heat into electricity has more than doubled compared to traditional values of ZT ∼ 1, reaching values even beyond ZT ∼ 2 in some instances. These improvements are mostly attributed to drastic reductions of the th...

Title of Dissertation: On-Chip Thermoelectric Cooling of Semiconductor Hot Spot Peng Wang, Doctor of Philosophy, 2007 Directed By: Professor Avram Bar-Cohen Assistant Professor Bao Yang Department of Mechanical Engineering The Moore’s Law progression in semiconductor technology, including shrinking feature size, increasing transistor density, and faster circuit speeds, is leading to increasing ...

Thermoelectric devices that are flexible and optically transparent hold unique promise for future electronics. However, development of invisible thermoelectric elements is hindered by the lack of p-type transparent thermoelectric materials. Here we present the superior room-temperature thermoelectric performance of p-type transparent copper iodide (CuI) thin films. Large Seebeck coefficients an...

Thermoelectric technology, harvesting electric power directly from heat, is a promising environmentally friendly means of energy savings and power generation. The thermoelectric efficiency is determined by the device dimensionless figure of merit ZT(dev), and optimizing this efficiency requires maximizing ZT values over a broad temperature range. Here, we report a record high ZT(dev) ∼1.34, wit...

We report in-plane thermoelectric power measurements on single crystals of (Ba1−xKx)Fe2As2(0.44≤x≤1). We observe a minimum in the S|T=const versus x at x∼0.55 that can be associated with the change in the topology of the Fermi surface, a Lifshitz transition, related to the electron pockets at the center of M point crossing the Fermi level. This feature is clearly observable below ∼75 K. Thermoe...

The demand for portable power is large and expanding. Technologies currently available to meet this demand include batteries, fuel cells, thermophotovoltaic (TPV) generators and thermoelectric (TE) generators. Fuel cells and generators offer significantly improved performance over batteries, but issues of fuel processing and miniaturization remain. Microfabrication has the potential to address ...

The spatially resolved thermoelectric power is studied on epitaxial graphene on SiC with direct correspondence to graphene atomic structures by a scanning tunneling microscopy (STM) method. A thermovoltage arises from a temperature gradient between the STM tip and the sample, and variations of thermovoltage are distinguished at defects and boundaries with atomic resolution. The epitaxial graphe...

Half-Heusler alloys ~MgAgAs type! with the general formula MNiSn where M is a group IV transition metal ~Hf, Zr, or Ti! are currently under investigation for potential thermoelectric materials. These materials exhibit a high negative thermopower (240 to 2250 mV/K) and low electrical resistivity values ~0.1–8 mV cm! both of which are necessary for a potential thermoelectric material. Results are...

This work presents the fabrication of thermopiles with high output voltage. A series of mixed thick/thin-film thermopiles were performed – one of the arms of the thermocouples was screen-printed (PdAgor Ag-based thick-film layers), the second was made of magnetron sputtered semiconductor (compositions based on Ge). The output parameters (thermoelectric force ET [V], internal resistance Ri [Ω], ...