Fig. 6

Tauc plots of (αhν)1/2 as a function of photon energy (hν) for indirect optical transitions (a) and plots of (αhν)2 as a function of photon energy (hν) for direct optical transitions (b).

Tauc plots of (αhν)1/2 as a function of photon energy (hν) for indirect optical transitions (a) and plots of (αhν)2 as a function of photon energy (hν) for direct optical transitions (b).