Near-Infrared Transparent Transition-Metal-Doped Indium Oxide Thin-Film Heater for LiDAR.

The evolving need for all-weather light detection and ranging (LiDAR) sensors and cameras for autonomous vehicles, remote sensing surveillance, and space exploration has spurred the development of transparent heaters. While LiDAR photon sources have shifted from the visible to the near-infrared (NIR) range, the use of transparent conductive oxides (TCOs) for heaters leads to significant optical losses due to their high plasmonic absorption and reflection in the NIR range. Although different TCO compositions can be employed to preserve transparency and electrical conductivity in this range, the choice of dopants, their concentrations, and the underlying mechanisms remain largely unknown. In this study, we present TCOs specifically designed for NIR applications with a focus on identifying new compositions that strike a balance between NIR transparency and electrical conductivity. We present a 4B-6B transition-metal-doped indium oxide thin-film heater that exhibits impressive NIR transmittance (>90%) surpassing that of commonly used indium tin oxide films. By incorporating effective dopants such as titanium, hafnium, and tungsten, we successfully reduced the resistivity and enhanced the electrical conductivity of indium oxide films. To enhance the practical utility of the film, we implemented post-treatments comprising argon plasma treatment and encapsulation with low-molecular-weight poly(dimethylsiloxane), which resulted in significantly improved performance. The optimized film exhibited a sheet resistance of 520 Ω/sq and excellent optical transmittance at 850 nm (89.1%), 905 nm (89.7%), and 1550 nm (92%). Moreover, we successfully integrated defogging and defrosting capabilities into a commercial LiDAR camera and demonstrated its reliable operation in challenging environments.

Kirigami Photopiezo Catalysts for Self-Sustainable Environment Remediation.

Photo(electro)-piezo catalysis has emerged as one of the most effective strategies for sustainable environmental remediation. While various (nano)materials have been investigated for enhancing the intrinsic properties related to the interfacial band structure, increasing the efficiency by integration of materials with rational design for stress-strain applications has not yet been considered. Herein, we introduce kirigami strain engineering to photopiezo catalysts for enhancing efficiency by increasing the magnitude of applied strain and density of bends. Macroscale stretching motion is converted into localized bending by a pliable kirigami structure using similar or even lower input energy, which can be easily modulated by natural waves. The kirigami structure leads to a significant enhancement (∼250%) in the degradation of dyes, and we discovered the significant contribution of the oxygen reduction pathway in the charge-transfer mechanism, which corresponds to the observed enhancement. The photopiezo catalytic effects of kirigami were further highlighted by the small water reservoir test, showing its feasibility in nature for self-sustainable environmental remediation that can be modulated using motions of winds, waves, and life vibrations.