Optical properties of tin-selenid films

Thermodynamic pathway for the formation of SnSe and SnSe2 polycrystalline thin films by selenization of metal precursors

“…For samples Se530 and Se570, shown in Figure 9 b), the same procedure was applied to the region 0.9-1.1 eV and it points to indirect allowed transitions with band gap energies of 0.94 and 0.96 eV. Similar results were obtained for samples obtained with different growth methods 8,15 . For higher photon energies, the best linear fittings were obtained for direct allowed transitions.…”

“…chemical vapor deposition. Vacuum environment techniques such as flash, conventional and reactive evaporation 8,10,12,13 , hot wall epitaxy 11 , atomic layer deposition 30 and pulsed laser deposition 31,32 can also be found in literature. For SnSe 2 thin films synthesis, Hady et al 33 successfully tested conventional thermal evaporation of Sn and Se, and SnSe 2 powders.…”

“…Tin monoselenide is a p-type semiconductor with a band gap close to 0.9 eV for indirect allowed transitions 8-10 and 1.2 eV for direct allowed transitions 8,[10][11][12][13][14][15] . SnSe melts congruently at 880 • C. There are two known polymorphous crystalline structures.…”

Cu2ZnSnSe4 thin film solar cells produced via co‐evaporation and annealing including a SnSe2 capping layer

“…Only a small contribution of the main CZTSe peak at 195 cm − 1 could be identified. This is due to the finite penetration depth of the 514‐nm laser line in SnSe, which exhibits an absorption coefficient well above 10 5 cm − 1 . Solar cells produced from these absorbers without removing the SnSe thin film did not result in working devices.…”

Structure and optical properties of nanocrystalline NiO thin film synthesized by sol–gel spin-coating method

“…Using the curve above the estimated values of the oscillator parameters E o , E d and E g were found to be 6.84, 8.89, and 3.42 eV, respectively. The values of refractive index, n(0), and the constant ε ∞ = n(0) 2 (for h → 0) extrapolated from the Wemple-DiDomenico model fit, and the high-frequency dielectric [23] are found equal n(0) = 2.01 and ε ∞ = 4.04. The relation between the lattice dielectric constant (ε L = n 2 ), wavelength ( ) and refractive index (n) is given by [24].…”