In this study, damage mechanisms in the FeB/Fe₂B coatings formed on the surface of AISI 304 steel are determined by adhesion tests. First, the boriding of the AISI 304 steel was carried out through the powder-pack method at 1223 K in the range from 2-10 h of exposure time. After treatment, Berkovich depth-sensing indentation test were conducted; the result showed tensil and compressive residual stresses in the FeB and Fe₂B, respectively. The adhesion of borided steels was evaluated by the Daimler-Benz Rockwell-C and scratch test. Based on the scratch tracks, the chipping was the predominant mechanism at 2 and 6 h, with critical loads of 35 and 43 N, respectively; while spalliation was determined at 27 N for 10 h. Also, hertzian and tensil cracks, buckling and compressive delamination were determined in the AISI 304 borided steel by scanning electron microscope.

The preparation of ultra-thin semi-transparent solar cells with potential applications in windows or transparent roofs entails several challenges due to the very small thickness of the layers involved. In particular, problems related to undesired inter-diffusion or inhomogeneities originated by incomplete coverage of the growing surfaces must be prevented. In this paper, undoped SnO₂, CdS, and CdTe thin films with thickness suitable for use in ultra-thin solar cells were deposited with a radiofrequency (RF) magnetron sputtering technique onto conductive glass. Preparation conditions were found for depositing the individual layers with good surface coverage, absence of pin holes and with a relatively small growth rate adapted for the control of very small thickness. After a careful growth calibration procedure, heterostructured solar cells devices were fabricated. The influence of an additional undoped SnO₂ buffer layer deposited between the conductive glass and the CdS window was studied. The incorporation of this layer led to an enhancement of both short circuit current and open circuit voltage (by 19 and 32%, respectively) without appreciable changes of other parameters. After the analysis of the cell parameters extracted from the current-voltage (I-V) curves, possible origins of these effects were found to be: Passivation effects of the SnO₂/CdS interface, blocking of impurities diffusion or improvement of the band alignment.