Suchergebnisse

The authors study the morphological evolution of magnetron-sputtered thin silver (Ag) films that are deposited on weakly interacting silicon dioxide (SiO2) substrates in an oxygen-containing (O-2) gas atmosphere. In situ and real-time monitoring of electrically conductive layers, along with ex situ microstructural analyses, shows that the presence of O-2, throughout all film-formation stages, leads to a more pronounced two-dimensional (2D) morphology, smoother film surfaces, and larger continuous-layer electrical resistivities, as compared to Ag films grown in pure argon (Ar) ambient. In addition, the authors data demonstrate that 2D morphology can be promoted, without compromising the Ag-layer electrical conductivity, if O-2 is deployed with high temporal precision to target film formation stages before the formation of a percolated layer. Detailed real-space imaging of discontinuous films, augmented by in situ growth monitoring data, suggests that O-2 favors 2D morphology by affecting the kinetics of initial film-formation stages and most notably by decreasing the rate of island coalescence completion. Furthermore, compositional and bonding analyses show that O-2 does not change the chemical nature of the Ag layers and no atomic oxygen is detected in the films, i.e., O-2 acts as a surfactant. The overall results of this study are relevant for developing noninvasive surfactant-based strategies for manipulating noble-metal-layer growth on technologically relevant weakly interacting substrates, including graphene and other 2D crystals. ; Funding Agencies|Linkoping University ("LiU Career Contract) [Dnr-LiU-2015-01510]; Swedish Research CouncilSwedish Research Council [VR-2015-04630]; Olle Engkvist Foundation [SOEB 190-312]; Wenner-Gren Foundations [UPD2018-0071, UPD2019-0007]; French Government Program "Investissements dAvenir" (LABEX INTERACTIFS)French National Research Agency (ANR) [ANR-11-LABX-0017-01]; Aforsk Foundation; European Consortium of Innovative Universities (ECIU)