Semiconducting and electrical properties of thin hybrid films from pyrrolyl- and anilynyl-silicon precursors

The semiconducting and electrical properties of as-deposited and ex-situ irradiated hybrid films on FTO and enriched in Cu 2024-T3 Al alloy substrates, using hydrolyzed solutions of pyrrolyl- (PySi) and anilinyl-silicon (AnSi) compounds, were investigated by means of photocurrent (PCS) and electrochemical impedance (EIS) spectroscopies. AnSi based film is p-type semiconducting while PySi is n-type due to OH-π interactions and charge pinning by silanol (SiOH). The electrical properties depend on the extent and nature of donor-acceptor complexes developed in solution, as well as on the propensity towards Cu+(π-ligand) coordination during the surface treatment step. The aniline derivative is more prone to Cu-π(N) complexation, which imparts stability to the buried interface. This, however, turns reactive in the presence of aggressive Cl− due to displacement reactions as the penetration of these species throughout the p-type semiconducting AnSi films is facilitated, contrariwise to the n-type PySi film.