In the current work, we present a detailed study on the material properties of the CIGS layers, fabricated on top of the CMOS chips, and compare the results with the fabrication on standard glass substrates. Almost identical elemental composition on both glass and CMOS chips (within measurement error). From X-ray diffraction measurement, except two peaks from the Si <100> substrate, the diffraction peaks from CIGS solar cell CMOS chip and that on glass substrate coincide for all three temperatures. Helium ion microscope images of the cross-section and top view of the CIGS layers, shows that the grain size is suitable for high efficiency solar cells.

We have synthesized single crystalline Ba8AlxSix-46 clathrates by using the flux Czochralski (CZ) method with Al-rich melt. The specific electric resistivity, the Seebeck coefficient and the power factor of single crystalline Ba8Al14Si32 were 0.73 mΩcm,70.0μV/K and 6.8×10-4 V2/K2Ωm, respectively. These values are higher than that of single crystalline Ba8Al12Si34 clathrate because of the reduced carrier concentration. It is indicated that Al contents and the carrier concentration of single crystalline Ba8AlxSi46-x can be controlled by using the flux Czochralski method.

Thermoelectric (TE) devices are solid state heat engines that directly convert thermal to electrical power (Seebeck Effect) and the reverse, electrical to thermal power (Peltier Effect). The phenomena were first discovered over 150 years ago and until recently have been more of a scientific curiosity than a practical technology of commercial interest. However, as governments impose regulations on greenhouse gas emissions and as the long-term availability of fossil fuels is questioned, alternative technologies, including thermoelectrics, are being explored to meet the challenges that arise from these new conditions.

Amerigon, the parent of BSST, is the largest supplier of thermoelectric (TE) devices to the automotive market. Over the last ten years BSST has been developing TE technology for the transportation market. Recent advancements at the system level made by BSST and improvements in TE materials made by several organizations indicate a path to improved performance and economic feasibility. This report discusses development of TE Generator (TEG) technology and of a TEG system installed in the power train of internal combustion engines for the purpose of converting waste heat to electric power. Our work has been made possible, in part, through sponsorship by the United States Department of Energy Office of Vehicle Technologies. The BMW Group, Ford Motor Company and Faurecia are partners in the BSST-led program.

Phase change materials (PCMs) often have higher specific energy storage capacities at elevated temperatures. Thermal management (TM) systems capable of handling high heat fluxes in the temperature range from 20–100°C are necessary but lacking. State of the art PCMs in this temperature range are usually paraffin waxes with energy densities on the order of a few hundred kJ/kg or ice slurries with energy densities of the same magnitude. However, for applications where system weight and size are limited, it is necessary to improve this energy density by at least an order of magnitude. The compound ammonium carbamate, [NH4][H2NCOO], is a solid formed from the reaction of ammonia and carbon dioxide which endothermically decomposes back to CO2 and NH3 in the temperature range 20-100°C with an enthalpy of decomposition of ∼2,000 kJ/kg. Various methods to use this material for TM of low-grade, high-flux heat have been evaluated including: bare powder, thermally conductive carbon foams, thermally conductive metal foams, hydrocarbon based slurries, and a slurry in ethylene glycol or propylene glycol. A slurry in glycol is a promising system medium for enhancing heat and mass transfer for TM. Progress on material and system characterization is reported.

The fabrication and characterization of released cantilevers in new multilayer thin films architectures is reported. In contrast to previous works, the cantilevers are produced without etching of the substrate and are based on lead free piezoelectric materials. The three architectures are: SrRuO3/BaTiO3/MgO/SrTiO3/YBa2Cu3O7, SrRuO3/BaTiO3/SrRuO3/YBa2Cu3O7 and SrRuO3/BaTiO3/SrRuO3/SrTiO3/YBa2Cu3O7. It is shown that the different architectures allow a choice of the orientation of the polar axis in piezoelectric layers, in plane (d33 mode) or out of plane (d31 mode). Both configurations may be utilized in piezoelectric energy harvesting devices. Released cantilevers with the above layer sequences have been produced with lengths ranging from, 100 μm to 250 μm. The residual stress after the release of the cantilevers produces an upward bending, the distance between the cantilever tips and the substrate varies between 20 μm and 45 μm. This distance would allow the sufficient vibration amplitude to enable the cantilevers to be used as micro-generators. Measurements of Young Modulus of the cantilevers and of polarization hysteresis loop are reported.

Hybrid piezoelectric composites were obtained by embedding barium titanate (BTO) nanofibers into a polyvinylidene fluoride (PVDF) matrix. Green BTO fibers were obtained by electrospinning a precursor polymeric solution under an electric field of 1 kV/cm. A network of non-woven ceramic BTO fibers was obtained after calcination of the green fibers. A PVDF solution was deposited over the ceramic fibers by spin-coating and then subjected to a low temperature heat treatment, to evaporate the solvent and promote the crystallization of the polar beta phase of PVDF.

In average, the diameter of the ceramic fibers ranged from 105 to 225 nm, presenting ribbon-like shape in some cases. Crystalline phases of BTO and PVDF were confirmed by X-ray diffraction and infrared spectroscopy, respectively. Polarization hysteresis curves revealed a ferroelectric behavior in all samples.