Experimental up-scaling of thermal conductivity reductions in silicon by vacancy-engineering: From the nano- to the micro-scale

A method to reduce the thermal conductivity in Si thin-films by at least an order of magnitude is shown, successfully demonstrating the up-scaling of this technique from Si nano-films. High energy self implantation of Si is used to create a supersaturation of lattice vacancy concentrations that remain following post implant rapid thermal annealing producing a disruption in phonon mode thermal transport. This method demonstrates an approach for micro-harvesting thermoelectric device applications without the difficulties faced for dimensional up-scaling in alternative Si thermoelectric approaches. Challenges surrounding the thermal budget required for post implant dopant activation in p-type Si are also shown.