Optical Band Gap and Electrical Conductivity of Doped Conducting Polypyrrole

AbstractThe material properties of laser-annealed a-Si:Nx films were investigated. The a-Si:Nx films for laser-annealing were deposited by rf plasma enhanced chemical vapor deposition (PECVD) with NH3 and SiH4 gas mixtures. At the 0.35 of NH3/SiH4 ratio, the optical band-gap was abruptly increased to 2.82 eV from 2.05 eV by laser-annealing which indicates that Si-N bonding comes to be notable at that ratio. The electrical conductivity showed the maximum value of 4× 10-6 S/cm at the 0.11 of NH3/SiH4 ratio where the grain growth and the increase of Si-N bonding are optimized for the enhancement of electrical conductivity. The σP/σD ratio which is related to the defects states for photo generation centers was decreased with increasing NH 3/SiH 4 ratio. Our experimental data showed that the optical band gap and electrical conductivity of laserannealed a-Si:Nx films were dominantly affected by the NH3/SiH4 ratio at the 250 mJ/cm2 of laser-annealing energy density.

Download Full-text

Electrical conductivity, density of states and optical band gap in Se90Te6Sn4 glassy semiconductor

Physica B Condensed Matter ◽

10.1016/j.physb.2012.10.018 ◽

2013 ◽

Vol 410 ◽

pp. 201-205 ◽

Cited By ~ 10

Author(s):

Mousa M.A. Imran ◽

Omar A. Lafi

Keyword(s):

Electrical Conductivity ◽

Band Gap ◽

Density Of States ◽

Optical Band Gap ◽

Glassy Semiconductor

Download Full-text

Absorber Films of Ag2S and AgBiS2 prepared by Chemical Bath Deposition

MRS Proceedings ◽

10.1557/proc-730-v5.14 ◽

2002 ◽

Vol 730 ◽

Cited By ~ 1

Author(s):

A. Nuñez Rodriguez ◽

M.T.S. Nair ◽

P.K. Nair

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrical Conductivity ◽

Silver Nitrate ◽

Band Gap ◽

Chemical Bath Deposition ◽

Optical Band Gap ◽

Sodium Thiosulfate ◽

Xrd Pattern ◽

Glass Substrates

AbstractAg2S thin films of 90 nm to 300 nm in thickness were deposited at 70°C on glass substrates immersed in a bath mixture containing silver nitrate, sodium thiosulfate and dimethylthiourea. When the films are heated in nitrogen at temperatures 200°C to 400°C, crystallinity is improved and XRD pattern similar to that of acanthite is observed. These films possess electrical conductivity of 10-3 (ohm cm)-1, are photoconductive and exhibit an optical band gap of 1.36 eV. When Ag2S thin film is deposited over a thin film of Bi2S3, also obtained by chemical bath deposition from bismuth nitrate, triethanolamine and thioacetamide, and heated at 300°C to 400°C in nitrogen, a ternary compound, AgBiS2 is formed. This material has an electrical conductivity of 5x10-5 (ohm cm)-1, is photoconductive and possesses optical band gap 0.95 eV.

Download Full-text

Effects of Sintering Atmosphere on the Optical, Thermal and Electrical Properties of Inkjet Printed ZnxCu(1-x)Fe2O4 Thin Films

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences ◽

10.37934/arfmts.81.2.2535 ◽

2021 ◽

Vol 81 (2) ◽

pp. 25-35

Author(s):

Lim Joon Hoong

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Band Gap ◽

Optical Band Gap ◽

Electronic Band Structure ◽

Copper Ferrite ◽

Electronic Band ◽

Sintering Atmosphere ◽

P Type

The effects of sintering atmosphere on the optical, thermal and electric properties of inkjet printed ZnxCu(1-x)Fe2O4 thin films have been investigated. The thin film samples were sintered separately in vacuum and oxygen. The obtained samples were then characterized by X-ray diffraction (XRD), optical band gap, electrical conductivity, Seebeck coefficient and thermal conductivity. XRD analysis showed that the fabricated samples have a cubic spinel structure of zinc copper ferrite regardless of the sintering atmosphere. The electrical conductivity of ZnxCu(1-x)Fe2O4 thin films sintered in oxygen was about 5 % higher compared to ZnxCu(1-x)Fe2O4 thin films sintered in vacuum. The optical band gap shows that the samples sintered in oxygen had smaller band gap compared to samples sintered in vacuum. The electronic band structure simulated through ABINIT shows ZnxCu(1-x)Fe2O4 is an indirect band gap material. A smaller electronic band gap was observed in O2 rich condition and was in agreement with the optical band gap and electrical conductivity test results. Seebeck coefficient of ZnxCu(1-x)Fe2O4 thin films sintered in oxygen remained positive , confirming charge transport by hole carries as p-type semiconductors. A change from p-type to n-type semiconductors was observed when ZnxCu(1-x)Fe2O4 thin films sintered in vacuum.

Download Full-text