TY - JOUR
T1 - Quasi-one-dimensional silicon nanostructures for gas molecule adsorption
T2 - a DFT investigation
AU - de Santiago, Francisco
AU - Santana, José Eduardo
AU - Miranda, Álvaro
AU - Trejo, Alejandro
AU - Vázquez-Medina, Rubén
AU - Pérez, Luis Antonio
AU - Cruz-Irisson, Miguel
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Porous structures offer an enormous surface suitable for gas sensing, however, the effects of their quantum quasi-confinement on their molecular sensing capacities has been seldom studied. In this work the gas-sensing capability of silicon nanopores is investigated by comparing it to silicon nanowires using first principles calculations. In particular, the adsorption of toxic gas molecules CO, NO, SO 2 and NO 2 on both silicon nanopores and nanowires with the same cross sections was studied. Results show that sensing-related properties of silicon nanopores and nanowires are very similar, suggesting that surface effects are predominant over the confinement. However, there are certain cases where there are remarked differences between the nanowire and porous cases, for instance, CO-adsorbed nanoporous silicon shows a metallic band structure unlike its nanowire counterpart, which remains semiconducting, suggesting that quantum quasi-confinement may be playing an important role in this behaviour. These results are significant in the study of the quantum phenomena behind the adsorption of gas molecules on nanostructure's surfaces, with possible applications in chemical detectors or catalysts.
AB - Porous structures offer an enormous surface suitable for gas sensing, however, the effects of their quantum quasi-confinement on their molecular sensing capacities has been seldom studied. In this work the gas-sensing capability of silicon nanopores is investigated by comparing it to silicon nanowires using first principles calculations. In particular, the adsorption of toxic gas molecules CO, NO, SO 2 and NO 2 on both silicon nanopores and nanowires with the same cross sections was studied. Results show that sensing-related properties of silicon nanopores and nanowires are very similar, suggesting that surface effects are predominant over the confinement. However, there are certain cases where there are remarked differences between the nanowire and porous cases, for instance, CO-adsorbed nanoporous silicon shows a metallic band structure unlike its nanowire counterpart, which remains semiconducting, suggesting that quantum quasi-confinement may be playing an important role in this behaviour. These results are significant in the study of the quantum phenomena behind the adsorption of gas molecules on nanostructure's surfaces, with possible applications in chemical detectors or catalysts.
KW - Chemical sensors
KW - Density functional theory
KW - Molecule adsorption
KW - Porous silicon
KW - Sensing
KW - Silicon nanowires
UR - http://www.scopus.com/inward/record.url?scp=85059347279&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2018.12.258
DO - 10.1016/j.apsusc.2018.12.258
M3 - Artículo
SN - 0169-4332
VL - 475
SP - 278
EP - 284
JO - Applied Surface Science
JF - Applied Surface Science
ER -