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Quantum confinement effects on the harmful‐gas‐sensing properties of silicon nanowires
Author(s) -
de Santiago Francisco,
Miranda Álvaro,
Trejo Alejandro,
Salazar Fernando,
Carvajal Eliel,
CruzIrisson Miguel,
Pérez Luis A.
Publication year - 2018
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.25713
Subject(s) - nanowire , adsorption , molecule , quantum dot , chemical physics , density functional theory , nanotechnology , potential well , materials science , hydrogen , electronic structure , range (aeronautics) , silicon , chemistry , computational chemistry , optoelectronics , organic chemistry , composite material
In this work, the effects of the adsorption of different toxic gas molecules CO, NO, NO 2 , and SO 2 on the electronic structure of hydrogen‐passivated, [111]‐oriented, silicon nanowires (H‐SiNWs), are studied through density functional theory. To analyze the effects of quantum confinement, three nanowire diameters are considered. The results show that the adsorption energies are almost independent of the nanowire diameter with NO 2 being the most strongly adsorbed molecule (∼3.44 eV). The electronic structure of small‐diameter H‐SiNWs is modified due to the creation of isolated defect‐like states on molecule adsorption. However, these discrete levels are eventually hybridized with the former nanowire states as the nanowire diameter increases and quantum confinement effects become less evident. Hence, there is a range of small nanowire diameters with distinctive band gaps and adsorption energies for each molecule species.