A Thermoelectric Generator Concept Using a p-n Junction: Experimental Proof of Principle

Conventional thermoelectric generators (TEGs) use single p- and n-doped legs for thermoelectric energy harvesting. We explore a concept using thermoelectric p-n junctions made from densified silicon nanoparticles. The nanoparticle powder was synthesized in a microwave plasma reactor using silane, diborane, and phosphine as precursors. To achieve a bulk sample with a p-n junction, a layer of boron-doped nanoparticle powder was stacked on a layer of phosphorus-doped powder and compacted by current-activated pressure- assisted densification. To use the p-n structure as a TEG, a temperature gradient was applied along the p-n junction. It is expected that this temperature gradient leads to electron-hole pair generation and separation in the junction, and diffusion of the charge carriers. A reference method was used to characterize the open-circuit voltage of the p-n junction TEG.