A study of the optical bandgap energy and Urbach tail of spray-deposited CdS:In thin films

Comparative study on structural, morphological and optical properties of Zn2SnO4 thin films prepared by r.f. sputtering using Zn and Sn metal targets and ZnO–SnO2 ceramic target

“…Due to the decrease of the structural disorder demonstrated in Figure 6 (b), the blue shift of the band gap observed for increasing film thickness can be explained in terms of reduced tail state spread, as already observed in [25][26].…”

Porous Quaternary Al0.1In0.1Ga0.8N Film Formation via Photoelectrochemical Etching in HF:C2H5OH Electrolyte

“…In order to determine the localized states present in the investigated films, according to the empirical Urbach's rule, following expression was used to determine Urbach energy ( U E ) of the localized states within the band gap,where α o is a constant while U E denotes the Urbach energy. The U E values were estimated by taking reciprocal of linear region in the log‐(α) vs hv plots .…”

Structure and optical properties of polycrystalline ZnSe thin films: validity of Swanepol’s approach for calculating the optical parameters

“…Three main regions contained the optical absorption spectra of the semiconductor; (i) the region generating from defects and impurities which is known as weak absorption region, (ii) the region generating from system disorder and structural perturbation which is known as absorption edge region, and (iii) the strong absorption region which determine the optical energy gap. The exponential part is known as Urbach tail which indicates the characteristic phenomena of absorption curve with respect to photon energy [46,47]. By using the band tail energy or Urbach energy (E urb ) value one can estimate the disorder level of the film structure.…”