Zuhair Subhani Khan

In the realm of renewable energy harvesting, nanomaterials doping with rare-earth ions is gaining traction. Lanthanum-doped ZnO thin films were synthesized using the sol–gel technique, with various La weight percentages. The X-ray diffraction (XRD) findings indicated that the hexagonal wurtzite structure of lanthanum-doped ZnO was maintained at various La weight percentage, despite a variation in the average crystallite size from 39 nm to 26 nm. The granule-like structure was examined using scanning electron microscopy (SEM), and the morphology remained unchanged with the inclusion of lanthanum. The direct energy bandgap was estimated to extend from 3.55 eV to 3.40 eV, revealing a discernible shift as the lanthanum concentration increased. The dc electrical conductivity of the films improved as the lanthanum doping in the ZnO lattice structure increased. Furthermore, increasing the La content altered the water contact angles from 51.5° to 26.4°, making the surface more hydrophilic. These findings can allow for the ubiquitous development of nanostructures for photoanode materials made of metal oxides with future applications in DSSC devices.

The development of organometal halide-based perovskite solar cells (PSCs) has made remarkable progress in photovoltaics. The commercialization of PSCs is still significantly limited, owing to their poor stability and the high material cost of a hole transport layer (HTL) and metal electrodes. To counter these issues, a carbon-based HTL and noble metal-free PSCs are being used. In this work, the effect of Cs-doping on perovskite film morphology and device performance has been systematically studied because the Cs⁺ and Br⁻ ions-doping has proved to be a good choice to improve the stability of PSCs in combination with a carbon electrode. The results showed that when the Cs-doping concentration in perovskite film, MA_1−xCs_xPb(I_1−yBr_y)₃, was equal to x = 0.09, there was a substantial change in the morphological and optoelectronic properties of perovskite films. The grain size of perovskite films was improved from 70 nm (x = 0.00 control) to 170 nm (x = 0.09 Cs-doped), reducing grain boundaries. Moreover, the trap states were additionally passivated resulting in improved radiative recombinations in the perovskite film. The device fabrication was carried out in a controlled dry glovebox, with relative humidity < 40% using carbon as a counter electrode. As a result, Cs-doped PSCs showed a significant increase in efficiency (5.27%) compared to control PSCs (1.55%).

Silicone rubber is a promising insulating material that has been performing well for different insulating and dielectric applications. However, in outdoor applications, environmental stresses cause structural and surface degradations that diminish its insulating properties. This effect of degradation can be reduced with the addition of a suitable filler to the polymer chains. For the investigation of structural changes and hydrophobicity four different systems were fabricated, including neat silicone rubber, a micro composite (with 15% micro-silica filler), and nanocomposites (with 2.5% and 5% nanosilica filler) by subjecting them to various hydrothermal conditions. In general, remarkable results were obtained by the addition of fillers. However, nanocomposites showed the best resistance against the applied stresses. In comparison to neat silicone rubber, the stability of the structure and hydrophobic behavior was better for micro-silica, which was further enhanced in the case of nanocomposites. The inclusion of 5% nanosilica showed the best results before and after applying aging conditions.