Supercapacitive performance of porous graphene nanosheets in bis(trifluoromethylsulfony)imide and bis(fluorosulfonyl)imide ionic liquid electrolytes

Journal of Solid State Electrochemistry - A method of high-heating-rate thermal reduction is used to produce porous graphene nanosheets (PGNSs). This material is characterized by a unique holey...     

Nanotribological behavior of ZnO films prepared by atomic layer deposition

We used atomic layer deposition to form ZnO thin-film coatings on Si substrates and then evaluate the effect of pile-up using the nanoscratch technique under a ramped mode. The wear volume decreased with increasing annealing temperature from room temperature to 400 °C for a given load. Elastic-to-plastic deformation occurred during sliding scratch processing between the groove and film for loading penetration of 30 nm. The onset of non-elastic behavior and greater contact pressure were evident for loading penetration of 150 nm; thus, full plastic deformation occurred as a result of a substrate effect. We suspect that elastic–plastic failure events were related to edge bulging between the groove and film, with elastic–plastic deformation attributable to adhesion discontinuities and/or cohesion failure of the ZnO films.     

Radiative recombination of indirect exciton in type-II ZnSeTe/ZnSe multiple quantum wells

The tunability of the emission energy, oscillator strength and photoluminescence (PL) efficiency by varying the well thickness and excitation density was demonstrated in the ZnSe_0.8Te_0.2/ZnSe multiple quantum wells. A significant blueshift about 260 meV of the PL peak energy was observed as the well width decreased from 5 to 1 nm. An extraordinary long lifetime (300 ns) of the recombination for the widest sample was detected. The binding energy of the indirect excitons is determined as 12 meV for the thinnest sample. The reduction of PL efficiency by thermal energy is greatly suppressed by employing a high excitation power.