Update on thermal diodes

Experiments on thermal diodes in InSb constructed with a p-type blocking layer in an n*pn structure have shown the existence of an optimum in acceptor concentration and width. Results for various potential barrier shapes show that triangle-shaped barriers outperform barriers with rectangular shape. Enhancements have been demonstrated in PbTe thermal diodes. In InSb and in PbTe diodes, the optimum width is on the order of the scattering length, which is different in the two semiconductors by an order of magnitude.