The reversibility of graphene photochemical chlorination was investigated. A high content of Cl is obtained through photochlorination, without changing C hybridization. To accommodate the incorporated Cl, graphene corrugation takes place. However, due to weak bonding, Cl atoms desorb during air exposure and long periods of storage. Chlorination also leads to graphene doping. When Cl is removed, doping decreases and graphene returns to its original morphology. Only a small amount of Cl (Cl/C ∼ 0.1) remains strongly bonded to graphene, most likely at grain edges and defects. Therefore, to maintain a precise doping level, Cl trapping methods are essential. Moreover, Cl removal using laser irradiation can be used to tune doping in micrometric areas, making it a promising technique to be used in applications where different doping levels are needed.

The thermal instability of GeO/Ge structures lasts as a barrier against the development of Ge-based metal-oxide-semiconductor devices. In the present work, stabilization was achieved through the incorporation of nitrogen into the oxide layer by thermally growing GeON films in NO. With this approach, a stable layer is obtained in a single step as opposed to other nitridation techniques (like plasma immersion) which require additional processing. Significant reduction of GeO desorption from the surface and a strong barrier against additional substrate oxidation were obtained by the insertion of a small amount of nitrogen content (N/O ≈ 10%). Nuclear reaction analysis and profiling showed that nitrogen incorporation and removal occur simultaneously during film growth, yielding N to be distributed throughout the whole film, without accumulation in any particular region. Both the oxidation barrier and the lower GeO desorption rate are explained by a reduction of vacancy diffusivity inside the dielectric. This is not caused by the densification of the oxide, but is a consequence of nitrogen blockage of oxygen vacancy diffusion paths.

MoS2 is a material with great potentialities in electronic applications. Tuning its properties by halogenation is a possible route to expand its applicability.

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