Laser-Etched Black Metal Surfaces for Ultra-Efficient Solar Thermoelectric Generators

Abstract

Solar thermoelectric generators (STEGs) convert sunlight to electricity via the Seebeck effect but have been limited by low temperature gradients and poor absorber/heat-sink management. Recent work demonstrates that femtosecond (fs) laser–etched “black metal” selective solar absorbers and laser-textured micro-structured heat dissipators substantially improve optical absorption and thermal management, enabling up to a 15× increase in STEG power output with modest weight penalty. Key advances are (1) creation of tungstenbased selective solar absorbers (W-SSA) with >80% solar absorptance and reduced IR emissivity, (2) encapsulation/greenhouse thermal management that cuts convective losses by >40%, and (3) laser-textured aluminum ?dissipators that double cold-side cooling capacity — together producing far higher ?T across TE modules and dramatically higher harvested power. This paper reviews the material- and device-level mechanisms, summarizes experimentally observed performance gains, presents comparative data, and discusses scalability and application prospects.

Keywords: Solar thermoelectric generator, femtosecond laser, black metal, selective solar absorber, thermal management, tungsten, microstructured heat sink