Tuning of Band Gap in Doped Diamonds*

Diamond as a material of extreme properties has already proved to be a very promising candidate for a vast variety of electronic applications, such as power switches, Schottky diodes, FETs and photovoltaics. To harness diamond properties at best, it is then crucial to understand how its entangled geometric and electronic properties determine the band gap.

To this aim, we conducted a quantum mechanical research on diamond structure doped with five different atoms (Al, B, N, P, Si) in three different concentrations (0.78%, 1.85%, 6.25%).  We performed advanced geometric and electronic analyses on the ground state structures, such as orbital polarization, bond covalency and Hirshfeld charges; in this way, we understood how to direct the spatial electronic density in order to obtain the desired band gap width.  We also propose guidelines on how to tune the character (direct/indirect) of the band gap and how such character is governed by the electronic distribution.

The outcomes of our investigation provide a compact source of information for further use in experimental and technical fields and can lead to the creation of the new semiconducting materials.