A flexible and widely applicable method allows the deposition of carbon-doped visible light-activated photocatalytic TiO 2 thin films on a variety of substrates.

We have studied the temperature dependence of the linewidth, Γ(T), of the fundamental absorption edge in bulk GaAs and four GaAs/Ga0.7Al0.3As single quantum wells of different well width using photoreflectance. As a result of the size dependence of the exciton-longitudinal optical phonon interaction, the thermal broadening of the linewidth diminishes as the dimensionality and size of the system are reduced.

Zinc Nitride (Zn3N2) films were grown by DC sputtering of a Zn target in a N2 plasma under a variety of different growth conditions, which resulted in the deposition of films with variable compositions. The as deposited films exhibited a polycrystalline Zn3N2 structure, which was converted to a ZnO-based structure after several weeks of ambient exposure. Zn3N2 films that were N-poor exhibited electrical properties indicative of a natively doped semiconductor and reached a minimum carrier concentration in the order of 1018 cm−3 at compositions, which approached the stoichiometric ratio of Zn3N2. A maximum carrier mobility of 33 cm2 V−1 s−1 was obtained in N-rich films due to an improved microstructure. The Zn3N2 films had an optical band gap of 1.31–1.48 eV and a refractive index of 2.3–2.7. Despite a wide range of Zn3N2 samples examined, little variation of its optical properties was observed, which suggests that they are closely related to the band structure of this material. In contrast to the as grown films, the oxidized film had a band gap of 3.44 eV and the refractive index was 1.6–1.8, similar to ZnO and Zn(OH)2.

No abstract

In this work, we present symmetric metal-insulator-metal bipolar memristors based on room-temperature deposition of charged titanium-oxide nanoparticles formed in vacuum by a physical process. One of the most striking features of these devices is that they do not require a forming step, which is to be related to protrusions of the top electrode material inside the intrinsically porous nanoparticle films. Furthermore, we report that deposition under substrate biasing conditions strongly affects the structural and electrical properties of the produced titanium oxide nanoparticle films including their bipolar switching behaviour.