Application of Hybrid rGO-ITO Bilayer TCO on a-Si Solar Cell for Performance Enhancement

Outstanding Room-Temperature Hydrogen Gas Detection by Plasma-Assisted and Graphene-Functionalized Core–Shell Assembly of SnO2 Nanoburflower

“…The Debye length L D for a semiconducting material could be calculated as 2 where “ k B ” is the Boltzmann constant; “ε” is the dielectric constant = ε o × ε r , where “ε r ” is the relative permittivity = ε/ε o ; “ε o ” is the permittivity of free space; “ T ” is the operating temperature in Kelvin scale; “ e ” is the electron charge (1.6 × 10 –19 C); and “ n d ” is the carrier concentration. 53,54 It has been estimated by the researchers that L D for SnO 2 is 3 nm with ε = 13.5, ε o = 8.85 × 10 –12 F/m, and n d = 3.6 × 10 24 m –3 . 3,8,25,53 Therefore, when the SnO 2 particle size is reduced to a size that is comparable to or lower than 2 L D , i.e., 6 nm, the whole crystallite will be fully depleted of electrons, which in turn causes the gas response of the element to change dramatically with D .…”

“…53,54 It has been estimated by the researchers that L D for SnO 2 is 3 nm with ε = 13.5, ε o = 8.85 × 10 –12 F/m, and n d = 3.6 × 10 24 m –3 . 3,8,25,53 Therefore, when the SnO 2 particle size is reduced to a size that is comparable to or lower than 2 L D , i.e., 6 nm, the whole crystallite will be fully depleted of electrons, which in turn causes the gas response of the element to change dramatically with D . Since L D for S10 sample is found to be 2.76 nm (overgrowth diameter), which is much lower than the critical size at which SnO 2 could exhibit the “size-related nanoeffect”, its gas sensing response pitched to its highest level.…”

“…The prominent effect of “nano” size, however, is associated with the thickness of the electron-depleted surface layer, which is defined as the Debye length “ L D ”. The Debye length L D for a semiconducting material could be calculated as where “ k B ” is the Boltzmann constant; “ε” is the dielectric constant = ε o × ε r , where “ε r ” is the relative permittivity = ε/ε o ; “ε o ” is the permittivity of free space; “ T ” is the operating temperature in Kelvin scale; “ e ” is the electron charge (1.6 × 10 –19 C); and “ n d ” is the carrier concentration. , It has been estimated by the researchers that L D for SnO 2 is 3 nm with ε = 13.5, ε o = 8.85 × 10 –12 F/m, and n d = 3.6 × 10 24 m –3 . ,,, Therefore, when the SnO 2 particle size is reduced to a size that is comparable to or lower than 2 L D , i.e., 6 nm, the whole crystallite will be fully depleted of electrons, which in turn causes the gas response of the element to change dramatically with D . Since L D for S10 sample is found to be 2.76 nm (overgrowth diameter), which is much lower than the critical size at which SnO 2 could exhibit the “size-related nanoeffect”, its gas sensing response pitched to its highest level.…”

Recovery of Cassiterite and Topaz Minerals from an Old Metallurgical Dump, Eastern Desert of Egypt

“…Because it is very resistant to all weathering influences, it is a typical placer mineral. There are no specifications for commercial concentrates of cassiterite because it is always smelted directly, depending on the concentration, without further treatment [5] [6].…”

Recovery of Cassiterite and Topaz Minerals from an Old Metallurgical Dump, Eastern Desert of Egypt

“…Because cassiterite is very resistant to all weathering in uences, it is a typical placer mineral. There are no speci cations for commercial concentrates of cassiterite because cassiterite is always smelted directly, depending on the concentration, without further treatment (Nandi et al 2019; Dalimunthe et al 2020).…”