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Abstract: Copper films with (111) texture are of crucial importance in integrated circuit interconnects. We have deposited strongly (111)-textured thin films of copper by atomic layer deposition (ALD) using [2,2,6,6-tetramethyl-3,5-heptadionato] Cu(II), Cu(thd)2, as the precursor. The dependence of the microstructure of the films on ALD conditions, such as the number of ALD cycles and the deposition temperature was studied by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy. Analysis of (111)-textured films shows the presence of twin planes in the copper grains throughout the films. SEM shows a labyrinthine structure of highly connected, large grains developing as film thickness increases. This leads to low resistivity and suggests high resistance to electromigration. [Copyright &y& Elsevier]

We have grown epitaxial thin films of Co3O4 on single-crystal MgO at ∼400°C by low-pressure thermal metalorganic chemical vapor deposition using cobalt(II) acetylacetonate as the precursor. X-ray phi-scan analysis shows that cube-on-cube epitaxy of Co3O4 occurs on MgO(1 0 0) in the temperature range ∼400–550°C. Films grown on MgO(1 0 0) at 410°C show a rocking curve FWHM of only 0.44°, despite a rather large lattice mismatch of 4.1%. This is interpreted to be due to the excellent match between the oxygen sublattices of Co3O4(1 0 0) and MgO(1 0 0). The strong epitaxy which occurs, leads to a low activation energy (Ea) for growth on MgO. Scanning electron microscopy analysis shows faceted grains characteristic of the cubic symmetry of Co3O4, the faceting being stronger at higher growth temperatures. [Copyright &y& Elsevier]

Abstract: Thin films of semiconducting, monoclinic, VO2(M) have been deposited on glass by atomic layer deposition (ALD). The composition and microstructure of the films have been examined by X-ray diffraction and scanning electron microscopy (SEM). The films deposited are VO2(M) phase, as deposited, and have been obtained at temperatures as low as 400°C. The films comprise largely of platelet morphology as illustrated by SEM. The semiconductor-metal transition near 340K leads to a large jump in resistivity in all the VO2(M) films, on glass, as deposited. The formation of VO2(M) phase has been shown to occur under very specific ALD conditions (ALD window). Growth kinetics, microstructure, and electrical properties have been studied as a function of deposition temperature. [Copyright &y& Elsevier]

The tin oxide (SnO 2) electron transport layer (ETL) plays a vital role in the photo-conversion efficiency (PCE) and stability of organic-inorganic perovskite solar cells (PSCs). However, SnO 2 ETL-induced defects such as hydroxyl groups, oxygen vacancies, exposed Sn atoms, and dangling bonds hinder device performance. In this study, rubidium chloride (RbCl) has been used to modify the SnO 2 ETL. Perovskite film formed on the RbCl-modified SnO 2 ETL exhibits improved crystallinity with enlarged grain size and reduced grain boundaries and enhanced optical absorption. The Hall-effect measurements indicate the improved carrier mobility, and the dark J-V curve shows the increment of electrical conductivity for the RbCl-modified SnO 2 ETL. X-ray photoelectron spectroscopy (XPS) results demonstrate the surface defects passivation of the perovskite layer by modifying the SnO 2 ETL. A champion PCE of 19.35% has been achieved for the RbCl-modified SnO 2 ETL-based devices with improved stability, while the control devices with unmodified SnO 2 ETL show a PCE of 17.18%. • RbCl-modified SnO 2 ETL exhibits improved crystallinity of the perovskite film. • The modification improves the carrier mobility and conductivity of ETL. • Modified ETL demonstrates the surface defects passivation of the perovskite layer. • A champion PCE of 19.35% has been achieved for the RbCl-modified SnO 2 ETL. [ABSTRACT FROM AUTHOR]