Effects of Al incorporation on structural and humidity-sensing properties of SnO2 sensor

Investigation on acceptor–donor co-doped SnO2 nanoparticles enriched with oxygen vacancies: a capacitive humidity sensor for respiration detection

“…10, the substitution of Al 3+ for Sn 4+ ions was consistently accompanied by the introduction of oxygen vacancies, where Al 3+ ions played an acceptor role and the Si dopants state functions as temporary trap centers. 32 The Si 3s orbitals and Al 3s orbitals have important contributions to the valence band which indicates that the crystalline and electronic structure has been changed with Al–Si co-doping in the SnO 2 . In the case of isovalent doping, the introduction of Si into SnO 2 is favorable for generating additional electrons and forming stable donor-like defects (Si Sn ) in the SnO 2 structure.…”