Optical properties of amorphous and polycrystalline Sb2Se3 thin films prepared by thermal evaporation

Abstract

Physical and optical properties of binary amorphous selenium-antimony thin films

Investigation of Physical and Electronic Properties of GeSe for Photovoltaic Applications

“…Furthermore, the minimum absorber layer thickness for full incident light absorption could be estimated by absorption coefficient based on the following formula: d = α −1 ln(T −1 ), [24] where T is the transmittance. Note that 1% of T represents the full light absorption in this calculation.…”

“…[28] For instance, optical coatings have been widely used in commercially available silicon modules to reduce severe reflection losses. The normal-incidence reflectivity from air to GeSe can be calculated based on the following formula [24,29] Adv. Electron.…”

“…Moreover, in the case of weakly or nonabsorbing region, the extinction coefficient was close to zero. The optical dispersion can be fitted to the wellknown Cauchy dispersion equation [24][25][26][27] ( ) 2 4…”

Band gap temperature-dependence of close-space sublimation grown Sb2Se3 by photo-reflectance

“…Specific advantages include low-costs, high deposition rates (e.g., several microns of CdTe within minutes), configuration versatility, and ease of scaling-up to meet production targets. 27 Despite the interest in Sb 2 Se 3 , considerable variance is seen in reports on the nature and magnitude of the band gap, which is variously claimed to be either indirect, ranging from 1.0 to 1.5 eV (either allowed 8,10,11,25,26 or forbidden 9 ), or direct 8,11 ranging from 1.2 to 1.9 eV. The fundamental gap is generally considered to be indirect with a direct gap lying at ∼0.1 eV to higher energy, 8 leading to very strong optical absorption: highly desirable in a PV absorber; in contrast, silicon has rather weak absorption until the direct onset at 3.2 eV.…”

“…22,23 While the precursory CdS/Sb 2 Se 3 layout (inherited from CdTe) allows the detrimental diffusion of Cd atoms across the junction interface, 5 performance improves with TiO 2 /Sb 2 Se 3 or ZnO/Sb 2 Se 3 architectures 5,24 and with a supplementary PbS hole-transport layer. 6 Prior Sb 2 Se 3 synthesis routes have included thermal evaporation, 3,5,8,18,25,26 chemical bath deposition, 12,26 Bridgman method, 9 solution or spin-coating, 12 RF sputtering, 26 and spray-deposition or pyrolysis. 25,26 This paper reports large Sb 2 Se 3 crystal grains grown by close-space sublimation (CSS), perhaps the simplest physical vapor deposition method.…”