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Abstract Moiré excitons (MXs) are electron-hole pairs localised by the periodic (moiré) potential forming in two-dimensional heterostructures (HSs). MXs can be exploited, e.g., for creating nanoscale-ordered quantum emitters and achieving or probing strongly correlated electronic phases at relatively high temperatures. Here, we studied the exciton properties of WSe2/MoSe2 HSs from T = 6 K to room temperature using time-resolved and continuous-wave micro-photoluminescence also under a magnetic field. The exciton dynamics and emission lineshape evolution with temperature show clear signatures that MXs de-trap from the moiré potential and turn into free interlayer excitons (IXs) for temperatures above 100 K. The MX-to-IX transition is also apparent from the exciton magnetic moment reversing its sign when the moiré potential is not capable of localising excitons at elevated temperatures. Concomitantly, the exciton formation and decay times reduce drastically. Thus, our findings establish the conditions for a truly confined nature of the exciton states in a moiré superlattice with increasing temperature and photo-generated carrier density.

A systematic investigation of the effect of hot-pressing on polyvinylidene fluoride (PVdF) - chlorotrifluoroethylene (CTFE) electrospun membranes, intended as separators and substrate for the electrolyte of lithium batteries, has been carried out by means of dynamic mechanical analysis. Absorption and desorption gravimetric measurements and infrared spectroscopy have been also performed. In particular, the mechanical properties of the membranes have been measured as a function of hot pressing temperature and pressure in the range 20 - 120 °C and 0 - 4 kbar, finding an increase of about 30 times of the tensile modulus after pressing at the highest temperature and pressure. Moreover, the conductivity of hot pressed membranes swelled by an ionic liquid measured as a function of temperature between - 60 and + 70 °C practically superimposes on that of the unpressed membrane.

We report a strain-induced direct-to-indirect band gap transition in mechanically deformed WS_{2} monolayers (MLs). The necessary amount of strain is attained by proton irradiation of bulk WS_{2} and the ensuing formation of 1-ML-thick, H_{2}-filled domes. The electronic properties of the curved MLs are mapped by spatially and time-resolved microphotoluminescence, revealing the mechanical stress conditions that trigger the variation of the band gap character. This general phenomenon, also observed in MoS_{2} and WSe_{2}, further increases our understanding of the electronic structure of transition metal dichalcogenide MLs and holds a great relevance for their optoelectronic applications.