Exciton states of titanium dioxide nanocrystals

Abstract

Using a variational method within the framework of an effective mass approximation, applying a triangular coordinate system of an electron, a hole and an exciton moving in a titanium dioxide nanocrystal, an exciton energy spectrum was obtained as a function of a radius of the nanocrystal particle. It was established that the optical absorption of anatase nanocrystal, observed in the experiment, was due to the appearance of an exciton in the nanocrystal. Using a variational calculation of the energy spectrum of the exciton in the nanocrystal, a position of an absorption peak was determined.