The on-surface self-assembly of inorganic atomic clusters and organic molecules offers significant opportunities to design novel hybrid materials with tailored functionalities. By adopting the advantages from both inorganic and organic components, the hybrid self-assembly molecules have shown great potential in future optoelectrical devices. Herein, we report the co-deposition of 4,8-diethynylbenzo[1,2-d-4,5-d0]bisoxazole (DEBBA) and Se atoms to produce a motif-adjustable organic–inorganic hybrid self-assembly system via the non-covalent interactions. By controlling the coverage of Se atoms, various chiral molecular networks containing Se, Se ₆, Se₈, and terminal alkynes evolved on the Ag(111) surface. In particular, with the highest coverage of Se atoms, phase segregation into alternating one-dimensional chains of non-covalently bonded Se₈ clusters and organic ligands has been noticed. The atom-coverage dependent evolution of self-assembly structures reflects the remarkable structural adaptability of Se clusters as building blocks based on the spontaneous resize to reach the maximum non-covalent interactions. This work has significantly extended the possibilities of flexible control in self-assembly nanostructures to enable more potential functions for broad applications.

We demonstrate that the intrinsic properties of monolayer graphene allow it to act as a more effective saturable absorber for mode-locking fiber lasers when compared to multilayer graphene. The absorption of monolayer graphene can be saturated at lower excitation intensity compared to multilayer graphene, graphene with wrinkle-like defects, or functionalized graphene. Monolayer graphene has a remarkably large modulation depth of 65.9%, whereas the modulation depth of multilayer graphene is greatly reduced due to nonsaturable absorption and scattering loss. Picosecond ultrafast laser pulses (1.23 ps) can be generated using monolayer graphene as a saturable absorber. Due to the ultrafast relaxation time, larger modulation depth and lower scattering loss of monolayer graphene, it performs better than multilayer graphene in terms of pulse shaping ability, pulse stability, and output energy.