Background: Roughly a third of the energy consumed by the U.S. manufacturing industry is discharged as thermal losses to the atmosphere or to cooling systems. waste heat is estimated to be over 10 quads/yr (1 quad = 1015 Btu) an amount equivalent to more than 1.72 billion barrels of oil. If we could harness a small fraction of the waste heat while satisfying the economic demands of cost versus performance then thermoelectric (TE) power generation could bring substantial positive impacts. Conventional Thermoelectric (TE) devices use a doped semiconductor material with two Ohmic contacts exhibit liner current-voltage (I-V) characteristics when voltage applied to the devices is swept from negative to positive (or vise versa). electrical power generated by a TE device depends on the area bounded by open circuit voltage (Voc) and short circuit current (Isc) therefore the optimum load line to extract the maximum electrical power is simply determined by a point on the liner I-V. Technology Description: UC Santa Cruz researchers have designed and developed a material platform that combines a semiconductor nanowire network and a semiconductor thin film integrated directly on a mechanically flexible metallic substrate; utilizing multiple materials to address various temperature ranges at which each material is most efficient to a given temperature gradient. Moreover UC Santa Cruz researchers have development thermoelectric (TE) devices that employ electrical junctions that cause non-linear current-voltage characteristics. The invention introduces electrical junctions within a TE device that skews a normal linear I-V curve and turn it into non-linear curve in which the area (i.e.electrical power generation) bounded by a point on the non-linear I-V curve Voc and Isc can be much larger than those obtained for the liner I- V curve. This new development significantly improves the performance of thermoelectric devices. Applications: Thermoelectric devices with rectifying current-voltage characteristics
Electrical power generation in thermoelectric devices.