During oxidation and reduction, there was also changes in the spectra in the UV Vis region. This happens regardless of whether the redox process happens via electrochemical charging or redox reagent treatment. In the case of oxidation, a blueshift in the onset wavelength was observed (Figure ). Exactly opposite changes (blueshift in the onset wavelength) was observed during reduction (Figure ). It is well known that the absorption onset is related to the bandgap which inturn in degenerate semiconductor is dominated by the Burstein-Moss effect. Upon reducing the nanocrystals, the electrons increase the number of electrons in the valence band and this raises the valence band.