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Organic solar cells (OSCs) have emerged as a promising technology for renewable energy generation due to their low cost, lightweight, flexibility, and compatibility with roll-to-roll manufacturing. However, OSCs still face challenges in achieving high power conversion efficiency (PCE) due to various factors, including recombination loss. In this study, we investigated the effect of introducing a layer of eight atomic percent gadolinium-doped zinc oxide (Zn0.92Gd0.08O) between the poly(3-hexylthiophene) (P3HT): [6,6]-phenyl butyric acid methyl ester (PCBM) active layer and the fluorine-doped tin oxide (FTO) electrode of the OSC. The reference cell, which has an Au/P3HT:PCBM/ZnO/FTO structure, exhibits a PCE of 0.52%. Remarkably, when the Zn0.92Gd0.08O layer was inserted (Au/P3HT:PCBM/Zn0.92Gd0.08O/FTO), the PCE increased significantly to 3.42%, which is more than six times the increase. Through further analysis, we present that the insertion of the Zn0.92Gd0.08O layer induces spin polarization in the P3HT:PCBM layer, leading to enhanced charge transport and reducing the recombination rate. Based on the findings, it can be concluded that the Zn0.92Gd0.08O film can potentially improve OSC performance. [ABSTRACT FROM AUTHOR]

Trivalent metal-doped TiO2 thin films have been extensively investigated in gas sensor applications. The trivalent metal dopants are Al, Y and Gd. The trilayer fabrication of a gas sensor consists of a thin film, sputtered TiO2 and Au nanoparticles. The characteristics of the gas sensing properties are strongly correlated with the annealing temperature, film thickness, type of doping and deposition method. The subsequent properties are presented - the crystalline structure, grain size, roughness, strain, stress and defects. Thin films have been developed with concentrations of O2 gas up to 10 sccm. A response time for O2 gas in milliseconds was obtained at room temperature. Al doped TiO2 thin film have a faster response time operating at room temperature compared with other thin films. Oxygen vacancy defects also contribute to the speed of the response time for a gas sensor. [ABSTRACT FROM AUTHOR]

The gist of biosensor is the sensing layer itself due to the ability to sense bio components such as bacteria. Graphene is an example of a promising material used as biosensor. Graphene material possess unique and superior properties and promised material to use as sensing layer due to its advantages in conductivity and large surface area. Escherichia coli is a group of bacteria causes harmful disease to human health due to its spreading in environment through faecal contaminated water. This study reports on biocompatibility of graphene against E. coli through visible growth inhibitory test and SEM image that evidently showed no inhibition growth and undamaged bacteria cell. Graphene wettability over water contact angle performed by hydrophobicity with 108.90° which preferably attached by the cells due to its surface energy condition. Negativity charge of bacteria enables to induce the holes of graphene then formed ohmic contact between the sheets and electrode. Based on its resistance, graphene could detect E. coli with limit detection of 4 CFU. Therefore, a compact and portable design of E. coli sensor was successfully fabricated with the device average error about 12.23%. • A novel, compact and portable design of E. coli sensor was successfully fabricated. • Biocompatibility of graphene against E. coli through visible growth inhibitory test and SEM image were presented. • Graphene material characterization was presented. • The negativity charge of bacteria could induce graphene film then produced ohmic contact between the sheets and electrode. • Increasing number of bacteria could decrease graphene resistivity. [ABSTRACT FROM AUTHOR]