Andrivo Rusydi

TL;DR: In this article, a surface La interstitial promoted interface insulator-metal transition in perovskite oxide interfaces has been proposed, and the results reveal the origin of the metal-insulator transition in these surfaces, and also shed light on the manipulation of the superior properties of these surfaces.

Abstract: We study the effects of post-annealing treatments on excitonic states and defects of nanostructured Ti-doped ZnO thin films grown by room-temperature magnetron sputtering technique. Here, the as-grown samples were annealed by varying the annealing environment, time, and temperature. We found that the higher excitonic emission was at 600 °C under N2 environment for 30 min. The excitonic states are analyzed by using spectroscopic ellipsometry, photoluminescence, and ultraviolet-visible absorption spectroscopy. Through critical point analysis of the complex dielectric function from spectroscopic ellipsometry, the energy of exciton is redshifted from 3.49 eV to 3.36 eV and the increase of excitonic transition is observed upon the annealing treatment. The weak excitonic transition in the as-grown sample is mainly due to the oxygen vacancies that promote electronic screening effect. The contribution of oxygen vacancies is confirmed by the presence of green luminescence (∼2.5 eV) and space-charge-limited current regime from electrical properties measurements. This work is very important for tunable optoelectronic devices based on the doped ZnO system.

TL;DR: In this article, the interference between superlattice and surface reflections was used to distinguish between scatterers in the SCO and the LCO layers, with the two hole states maximized in different layers of the super lattice.

TL;DR: In this paper, a set of sample consisting of pure ZnO and Cu-doped znO film were grown on fused-quartz substrates using pulsed laser deposition (PLD) technique.