Furthermore,
the optical band gap of three-dimensional (3D) hierarchical
flower-like CTS microspheres was evaluated to be 1.38 eV
by Chen et al.,6) who stated the potential application in solar
energy conversion and photocatalysis. Optical properties of
CTS sprayed thin film with 500 C annealing were measured
and the direct energy gap of the film was determined by
Bouaziz et al. to be 1.22 eV.7) The energy band gap of
tetragonal CTS with 500 C sulfurization temperature was
reported by Guan et al. to be 1.22 eV.8)