Due to their excellent properties, Zinc oxide nanowires (ZnO NW) have been attractive and considered as a promising electron-transporting layer (ETL) in flexible Perovskite Solar Cells (FPSCs). Since the first report on ZnO NWs-based FPSCs giving 2.6 % power conversion efficiency (in 2013), great improvements have been made, allowing to reach up to∼15 % nowadays. However, some issues still need to be addressed, especially on flexible substrates, to achieve uniform and well-aligned ZnO NWs via low-cost chemical solution techniques. Several parameters, such as the growing method (time, temperature, precursors concentration), addition of seed layer (thickness, roughness, annealing temperature) and substrate (rigid or flexible), play a crucial role in ZnO NWs properties (i.e., length, diameter, density and aspect ratio). In this review, these parameters allowing to control the properties of ZnO NWs, like the growth techniques, utilization of seed layers and the growing method (time or precursors concentration) have been summarized. Then, a particular focus on the ZnO NW's role in FPSCs as well as the use of these results on the development of ZnO NWs-based FPSCs have been highlighted.

Electron and hole transport layers (ETL and HTL) play an essential role in shaping the photovoltaic performance of perovskite solar cells. While compact metal oxide ETL have been largely explored in planar n-i-p device architectures, aligned nanowires or nanorods remain highly relevant for efficient charge extraction and directional transport. In this study, we have systematically grown ZnO nanowires (ZnO NWs) over aluminum-doped zinc oxide (AZO) substrates using a low-temperature method, hydrothermal growth (HTG). The main growth parameters were varied, such as hydrothermal precursors concentrations (zinc nitrate hexahydrate, hexamethylenetetramine, polyethylenimine) and growing time, in order to finely control NW properties (length, diameter, density, and void fraction). The results show that ZnO NWs grown on AZO substrates offer highly dense, well-aligned nanowires of high crystallinity compared to conventional substrates such as FTO, while demonstrating efficient FACsPb(IBr)₃ perovskite device performance, without the requirement of conventional compact hole blocking layers. The device performances are discussed based on NW properties, including void fraction and aspect ratio (NW length over diameter). Finally, AZO/ZnO NW-based devices were fabricated with a recent HTL material based on a carbazole moiety (Cz–Pyr) and compared to the spiro-OMeTAD reference. Our study shows that the Cz–Pyr-based device provides similar performance to that of spiro-OMeTAD while demonstrating a promising stability in ambient conditions and under continuous illumination, as revealed by a preliminary aging test.

In the rapidly advancing field of medical microrobotics, designing robots capable of addressing various challenges—such as imaging, biodegradation, and multifunctionality—is crucial. Departing from conventional research that often focuses on isolated aspects of microrobot functionality, this study presents an innovative approach to comprehensive microrobot design. Soft capsule microrobots that integrate capabilities such as magnetic navigation, autonomous maneuverability, in situ biodegradation, biosafe imaging, and drug delivery are reported. These microrobots are fabricated within the range of 20–120 μm, with a notable throughput of ≈10²–10³ microrobots per second. Furthermore, their locomotion performance has been demonstrated to remain stable for a period exceeding 10 h, all while employing real‐time optical closed‐loop control. The incorporation of ultrasound contrast agents not only amplifies imaging resolution but also ensures imaging contrast stability in a biological environment for over a period of 3 h. Second, the intentional integration of enzyme‐loaded nanometric polymersomes establishes a self‐contained, biodegradable system, accentuating the microrobots’ capacity to degrade without the addition of high enzyme concentrations. This integrated approach lays the groundwork for minimally invasive treatments toward personalized and targeted medicine.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.