Correction: Optimized Cu-doping in ZnO electro-spun nanofibers for enhanced photovoltaic performance in perovskite solar cells and photocatalytic dye degradation.

[This corrects the article DOI: 10.1039/D4RA01544D.].

Optimized Cu-doping in ZnO electro-spun nanofibers for enhanced photovoltaic performance in perovskite solar cells and photocatalytic dye degradation.

Perovskite solar cells (PSCs) compete with conventional solar cells regarding their low-temperature processing and suitable power conversion efficiency. In PSCs, the electron transport layer (ETL) plays a vital role in charge extraction and avoiding recombination; however, poor charge transport of ETL leads to high internal resistance and associated low fill factors. To successfully resolve this challenge, copper-doped zinc oxide nanofibers as an electron transport layer are prepared with various doping levels of 1, 2, and 3 wt% using the electrospinning sol-gel method. The 3 wt% doping of Cu revealed the optimum performance as an ETL, as it offers an electrically efficient transporting structure. SEM images revealed a randomly oriented distribution of nanofibers with different sizes having mesoporous uniformity. Optical properties of doped nanofibers examined using UV-visible analysis showed an extended light absorption due to heteroatom-doping. Adding Cu into the ZnO leads to enhanced charge mobility across the electron transport material. According to Hall measurements, dopant concentration favors the conductivity and other features essentially required for charge extraction and transport. The solar cell efficiency of ZnO doped with 0%, 1%, 2%, and 3% Cu is 4.94%, 5.97%, 6.89%, and 9.79%, respectively. The antibacterial and photocatalytic activities of the prepared doped and undoped ZnO are also investigated. The better light absorption of Cu-ZnO showed a pronounced improvement in the photocatalytic activity of textile electrodes loaded with doped ZnO. The dye degradation rate reaches 95% in 180 min under visible light. In addition, these textile electrodes showed strong antibacterial activity due to the production of reactive oxygen species under light absorption.

Room Temperature Synthesized TiO2 Nanoparticles for Two-Folds Enhanced Mechanical Properties of Unsaturated Polyester.

Using of nano-inclusion to reinforce polymeric materials has emerged as a potential technique to achieve an upper extreme of specific strength. Despite the significant improvement of mechanical properties via nano-reinforcements, the commercial application of such nano-composites is still restricted, due to high cost and unwanted aggregation of nanoparticles in the polymer matrix. To address these issues, here we proposed a scalable and economical synthesis of TiO2 at low temperatures, resulting in self-dispersed nanoparticles, without any surfactant. As lower energy is consumed in the synthesis and processing of such nanoparticles, so their facile gram-scale synthesis is possible. The defect-rich surface of such nanoparticles accommodates excessive dangling bonds, serving as a center for the functional groups on the surface. Functional surface enables high dispersion stability of room temperature synthesized TiO2 particles. With this motivation, we optimized the processing conditions and concentration of as-synthesized nano-particles for better mechanical properties of unsaturated polyester (UP) resin. The composite structure (UP-TiO2) showed nearly two folds higher tensile, flexural, and impact strength, with 4% content of nanoparticles. Characterization tools show that these better mechanical properties are attributed to a strong interface and superior dispersion of nanoparticles, which facilitate better stress distribution in the composite structure. In addition, the crack generation and propagation are restricted at a much smaller scale in nanocomposites, therefore significant improvement in mechanical properties was observed.

Efficient Tuning of the Opto-Electronic Properties of Sol-Gel-Synthesized Al-Doped Titania Nanoparticles for Perovskite Solar Cells and Functional Textiles.

The efficient electron transport layer (ETL) plays a critical role in the performance of perovskites solar cells (PSCs). Ideally, an unobstructed network with smooth channels for electron flow is required, which is lacking in the pristine TiO2-based ETL. As a potential solution, here we tuned the structure of TiO2 via optimized heteroatom doping of Al. Different concentrations (1, 2, and 3 wt%) of Al were doped in TiO2 and were successfully applied as an ETL in PSC using spin coating. A significant difference in the structural, opto-electronic, chemical, and electrical characteristics was observed in Al-doped TiO2 structures. The opto-electronic properties revealed that Al doping shifted the absorption spectra toward the visible range. Pure titania possesses a bandgap of 3.38 eV; however, after 1, 2, and 3% Al doping, the bandgap was linearly reduced to 3.29, 3.25, and 3.18 eV, respectively. In addition, higher light transmission was observed for Al-doped TiO2, which was due to the scattering effects of the interconnected porous morphology of doped-TiO2. Al-doped titania shows higher thermal stability and a 28% lower weight loss and can be operated at higher temperatures compared to undoped titania (weight loss 30%) due to the formation of stable states after Al doping. In addition, Al-doped TiO2 showed significantly high conductivity, which provides smooth paths for electron transport. Thanks to the effective tuning of band structure and morphology of Al-doped TiO2, a significant improvement in current densities, fill factor, and efficiency was observed in PSCs. The combined effect of better Jsc and FF renders higher efficiencies in Al-doped TiO2, as 1, 2, and 3% Al-doped TiO2 showed 12.5, 14.1, and 13.6% efficiency, respectively. Compared to undoped TiO2 with an efficiency of 10.3%, the optimized 2% Al doping increased the efficiency up to 14.1%. In addition, Al-doped TiO2 also showed improvements in antibacterial effects, required for photoactive textiles.