Method for forming thermoelectric element using electrolytic etching

摘要

The present disclosure provides a thermoelectric element comprising a flexible semiconductor substrate having exposed surfaces with a metal content that is less than about 1% as measured by x-ray photoelectron spectroscopy (XPS) and a figure of merit (ZT) that is at least about 0.25, wherein the flexible semiconductor substrate has a Young's Modulus that is less than or equal to about 1×106 pounds per square inch (psi) at 25° C.

主权项

1. A method for forming a thermoelectric element having a figure of merit (ZT) that is at least 0.25 at 25° C., comprising:
(a) providing a reaction space comprising a semiconductor substrate, a working electrode in electrical communication with a first surface of said semiconductor substrate, an etching solution in contact with a second surface of said semiconductor substrate, and a counter electrode in said etching solution, wherein said first and second surfaces of said semiconductor substrate is substantially free of a metallic coating; and (b) using said working electrode and said counter electrode to (i) direct electrical current to said semiconductor substrate at a current density of at least 0.1 mA/cm2, and (ii) etch said second surface of said semiconductor substrate with said etching solution to form a pattern of holes in said semiconductor substrate, thereby forming said thermoelectric element having said ZT that is at least 0.25, wherein said etch is performed at an electrical potential of at least 1 volt (V) across said semiconductor substrate and said etching solution, and wherein said etch has an etch rate that is at least 1 nanometer (nm) per second at 25° C.