Resonant level-induced high thermoelectric response in indium-doped GeTe

The promising heat-to-electricity conversion efficiency of phase-change materials can be enhanced with indium dopants. Germanium telluride (GeTe) has a high thermoelectric response because it stores latent heat through temperature-dependent changes to its crystal phase. Now, researchers in China and the USA have used quantum simulations to investigate electronic routes to further boost energy harvesting by GeTe. Their computations searched through numerous chemical elements and found that adding small quantities of indium atoms opens up new resonant energy levels that could lead to extra heat retention in both of GeTe's phases. Experimental synthesis of indium-doped GeTe demonstrated the validity of this approach, with optimized samples showing a 70% improvement in thermoelectric conversion across a wide temperature range.