Silicon-based film may hold key to efficient thermoelectric devices

摘要

Computers, light bulbs, and even people generate heat, and a thermoelectric device can harness that otherwise wasted energy. But present-day thermo-electric designs are not efficient enough for widespread commercial use or are made from rare materials that are expensive and harmful to the environment. Researchersrnat the California Institute of Technology in Pasadena (Caltech) have developed a new type of material, made out of silicon, that could lead to more efficient thermoelectric devices. The material-a type of nanomesh-is com-posed of a thin film with a grid-like arrangement of tiny holes. This unique design makes it difficult for heat to travel through the material, lowering its thermal conductivity to near silicon's theoretical limit. At the same time, the design allows electricity to flow as well as it does in unmodified silicon.