A hot carrier photovoltaic cell by offset resonant tunneling

Conventional single junction photovoltaic cells are fundamentally limited to efficiencies below 31%. We explore the possibilities provided by a hot carrier approach to photovoltaic power conversion, which is capable of approaching the fundamental thermodynamic efficiency limit of 85%. We discuss the two fundamental requirements of a hot carrier cell and how these are realized in a prototype structure. We show how three features of this structure limit its efficiency and go on to summarize our recent experimental verification of such a cell.