The efficiency is one of the biggest challenges for solar cells: most of the sun's incoming light is dissipated as heat, not converted to electricity. In the Shockley-Queisser detailed balance analysis, power conversion efficiency is limited to ~ 33% for a single light-absorbing layer.

The multiple exciton generation (MEG) is a process where several charge carriers are generated upon the absorption of a single photon in semiconductors. Therefore, MEG is the promising way to overcome the standard thermodynamic limit of the solar cells efficiency. Through the significant electronic coupling between impurity-induced density of states in nanostructured materials, MEG efficiency can be also remarkably tuned and improved by chemical doping and functionalization. Using first-principles calculations, we will focus on predicting optimal chemical doping and functionalization conditions for the maximal MEG.

In addition, the efficiency of energy conversion and storage devices strongly relies on the structure and properties of the component materials. Moreover, they are controllable through the chemical doping and functionalization. Using first-principles calculations, we will focus on understanding the role of doping and functionalization, and predicting optimal doping conditions for the development of efficient energy conversion and storage.