Abstract:We reported on the generation of femtosecond pulse in an anomalous-dispersion fiber ring laser by using a polyvinyl alcohol (PVA)-based Topological Insulator (TI), Bi 2 Se 3 saturable absorber (SA). The PVA-TI composite has a low saturable optical intensity of 12 MW/cm 2 and a modulation depth of ~3.9%. By incorporating the fabricated PVA-TISA into a fiber laser, mode-locking operation could be achieved at a low pump threshold of 25 mW. After an optimization of the cavity parameters, optical pulse with ~660 fs centered at 1557.5 nm wavelength had been generated. The experimental results demonstrate that the PVA could be an excellent host material for fabricating

Here we demonstrate a new route to achieve the sintering of silver nanoparticles (Ag NPs) at room temperature. The as-prepared Ag NPs coalesced when they were immersed in electrolyte solutions, such as NaCl and MgSO 4 . The square resistances of Ag NPs thin films decreased from tens of kiloohms to lower than 1 ohm after treatment with electrolyte solutions for 10 s. Conductive Ag NPs thin films can be created on various substrates coated by polydopamine, a mussel-inspired polymer, via silver-plating followed by treatment with electrolyte solutions at room temperature. Experimental Fabrication of the polydopamine coating on substratesCommercially available glass, SiO 2 ceramics, polypropylene (PP), poly(ethylene terephthalate) (PET), silicon wafer, poly

Spiro-thiophene derivatives act as promising hole transport materials for highly efficient perovskite solar cell application.