With the synergistic effect of Pr and Zn, the material of Co3O4 mixed with Pr/Zn exhibits improved properties of anti-humidity and acetone sensitivity.
Due to the emerging requirements of miniaturization and multifunctionality, monolithic devices with both functions of lighting and detection are essential for next-generation optoelectronic devices. In this work, based on freestanding (In,Ga)N films, we demonstrate a monolithic device with two functions of lighting and self-powered detection successfully. The freestanding (In,Ga)N film is detached from the epitaxial silicon (Si) substrate by a cost-effective and fast method of electrochemical etching. Due to the stress release and the lightening of the quantum-confined Stark effect (QCSE), the wavelength blueshift of electroluminescent (EL) peak is very small (<1 nm) when increasing the injection current, leading to quite stable EL spectra. On the other hand, the proposed monolithic bifunctional device can have a high ultraviolet/visible reject ratio (Q = 821) for self-powered detection, leading to the excellent detection selectivity. The main reason can be attributed to the removal of Si by the lift-off process, which can limit the response to visible light. This work paves an effective way to develop new monolithic multifunctional devices for both detection and display.
In-plane anisotropy induced by a low-symmetric lattice structure in two-dimensional (2D) van der Waals (vdWs) materials has significantly promoted their applications in optoelectronic devices, especially in polarization photodetection. Given the mature preparation technology of transition metal dichalcogenides (TMDCs), introducing artificial anisotropy into symmetric TMDCs becomes a promising way to trigger more excellent functionalities beyond their intrinsic properties. Herein, monolayer MoS2 in the MoS2/Ta2NiSe5 vdWs heterostructure presents obvious anisotropic optical properties confirmed by polarized Raman and photoluminescence spectra, which is mainly ascribed to the uniaxial strain via strong interlayer couplings. Moreover, the MoS2/Ta2NiSe5 heterojunction endows unique orientation-selected polarized absorbance. In the visible region, the dominant polarized orientation is along the armchair axis while rotated to the perpendicular direction in the near-infrared spectrum, which is mainly ascribed to the intrinsic linear dichroism of Ta2NiSe5. The results suggest that the MoS2/Ta2NiSe5 heterostructure provides a promising platform for artificial regulation of the optoelectronic properties of symmetric MoS2 and integrated optical applications in the polarization-sensitive photodetection.
In this work, ZIF-8-derived Co3O4@ZnO microspheres were prepared by a liquid-phase concentration-controlled nucleation strategy. The results of the material characterization showed that Co3O4@ZnO microspheres were obtained, and the surface structure could be controlled with the concentration of the ligand. Compared with pure Co3O4 microspheres, the operating temperature of optimized Co3O4@ZnO microspheres increased by 90 °C after the gas-sensing test. The response to 50 ppm acetone of Co3O4@ZnO microspheres was 4.5 times higher than that of pure Co3O4, and the detection limit reached 0.5 ppm. Meanwhile, Co3O4@ZnO microspheres showed a shorter response-recovery time and better selectivity. The enhanced-sensing mechanism of the ZIF-8-derived Co3O4@ZnO microspheres was also analyzed.
Acetone is a main respiratory marker for diabetic patients. In this paper, P-type NiO nanofibers were prepared by electrospinning and used for the detection of acetone gas. NiO nanofibers were characterized by SEM and XRD. The uniform NiO nanofibers with face-centered cubic structure was obtained. The working temperature of NiO nanofibers was optimized, and the optimal operating temperature is 220°C. The response-recovery curve was tested, and the response and recovery time is 24.6 s and 610 s respectively. The response to different concentrations of acetone was also analyzed, and the detection limit was 100 ppb. These results show that NiO nanofibers based on electrospinning have potential applications in the respiratory testing of diabetes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.