Evaluation of spectral dispersion of optical constants of a-Se films from their normal-incidence transmittance spectra using Swanepoel algebraic envelope approach

High Photosensitive Indium–Gallium–Zinc Oxide Thin-Film Phototransistor with a Selenium Capping Layer for Visible-Light Detection

“…17 According to the Tauc plots and UPS spectra, energy band alignment of the IGZO and Se films was performed as shown in Figure 5d. The Se showed p-type semiconductor behavior, as also determined elsewhere, 40 and formed a p−n junction with the IGZO, which resulted in a large difference in the valence band maximum and a small difference in the conduction band minimum. In this energy band structure, photogenerated electron−hole pairs are easily separated by the built-in electric field at the p−n junction, and the electrons photogenerated in the SCL are easily transported into the IGZO layer.…”

Evaluation of Kinetic Parameters and Thermal Stability of Melt-Quenched BixSe100-xAlloys (x ≤7.5 at%) by Non-Isothermal Thermogravimetric Analysis

“…Undoped amorphous selenium (α -Se) is a twofoldcoordinated glassy p-type semiconductor with high dark electrical resistivity (~10 12 Ω cm at 300 K) and bandgap energy E g as large as 2 eV at 300 K (Bettsteller et al, 1993;Jafar et al, 2016;Mott & Davis, 1979;Saleh et al, 2017). Yet, undoped α-Se has minor photosensitivity for electromagnetic radiation of red wavelengths and larger (Bettsteller et al, 1993;Jafar et al, 2016;Mott & Davis, 1979).…”

“…Yet, undoped α-Se has minor photosensitivity for electromagnetic radiation of red wavelengths and larger (Bettsteller et al, 1993;Jafar et al, 2016;Mott & Davis, 1979). In addition, unwanted thermal-/photo-crystallization features of pure a-Se at low ambient temperatures, due to its low glasstransition temperature T G (around 45°C), make it of unstable structure and short working lifetime arising from ageing effects and thermal instability that lead to adverse changes in its physical properties (Innami & Adachi, 1999;Kasap et al, 1990;Saleh et al, 2017;Tonchev & Kasap, 2002). A practical approach that may enhance photosensitivity of α-Se to long-wavelength light, besides reducing its ageing features, improving its thermal stability and reforming its structure for use in various technical applications, is to alloy it with the other chalcogens (tellurium [Te] or sulfur [S]) and/ or with metallic/non-metallic elements to form binary (or ternary) Se-based chalcogenide glasses (Kasap & Rowlands, 2000;Kotkata et al, 2009;Mehra et al, 1993;Mehta, 2006;Mott & Davis, 1979;Saxena & Bhatnagar, 2003).…”