Abstract A strain modulated solar‐blinded photodetector (PD) based on ZnO‐Ga 2 O 3 core–shell heterojuction microwire is developed. This PD is highly sensitive to deep UV light centered at 261 nm. It performs ultrahigh sensitivity and spectral selectivity, which can response to rare weak deep UV light (≈1.3 µw cm −2 ) and almost no response to visible light wavelength ranges. Moreover, by using the piezo‐phototronic effect, the deep UV current response is enhanced to about three times under −0.042% static strain. This is a three way coupling effect among pizoelectric polarization, simiconductor properties, and optical excitation, which exists in noncentral symmetric wurtzite semiconductors such as ZnO, GaN, and CdS. By modulating the energy band diagrams and charge carriers in the junction area upon straining, the optoelectronic processes are regulated. The strain induced piezopotential modulates carrier transport in the heterostructure, which improves the response of the PD, with potential applications for health monitoring, smart systems, deep space exploration, and security communication.
Abstract With the emergence of disposable electronics, compatible safe, flexible, and recyclable power sources have become a critical challenge. Here, an ultra‐thin paper‐based iontronic power source is enabled by highly efficient translational Li + transport within 2D nanofluidic channels of graphene oxide under a salinity gradient and the fine‐tuned interfacial redox reactions. The paper‐based source can generate volumetric power and energy densities of 438.02 mW cm −3 and 30.02 mWh cm −3 , respectively. Its areal power density is 1095.05 mW cm −2 , surpassing most flexible batteries. It maintains a working state when bent or even cut and can be simply recycled by incineration. By filling 2D nanofluidic inks in different pens, the power source can be drawn on paper when needed, which not only overcomes the inherent defect of self‐discharge for most batteries but also enables writing directly on any insulating substrates. Furthermore, all‐in‐one disposable electronics comprised of an energy management system (paper‐based triboelectric nanogenerator and iontronic power source) and wireless sensing system (temperature sensor with NFC circuits) are integrated onto one piece of paper by duplex printing, demonstrating the huge potential of such integratable iontronic power sources for soft, wireless, and conformable disposable electronics.
Abstract Wind energy, one of the most promising and renewable energy sources, is extensively exploited around the world. However, in traditional triboelectric nanogenerator (TENG) for wind energy harvesting, due to the limitations of device structures with high friction force, the collection of wind energy at low speeds is always faced with enormous challenges. To overcome this difficulty, an ultralow friction and highly effective windmill‐like nanogenerator (WNG) is proposed. Herein, the WNG is based on a freestanding mode TENG and adopts a rotational triboelectric layer with contact–separation mode. This special design successfully achieves a smaller friction resistance, allowing wind energy to be captured at low speeds. Under the minimum wind speed, the optimized WNG has a maximum load power of 0.753 µW, which can illuminate nine LEDs simultaneously. The WNG can convert wind energy into enough electricity to power a hygrometer or a digital clock under the maximum wind speed. Moreover, a wind speed detection system based on WNG is developed and proves the superiority of real‐time wind speed detection by appropriate computation parameters. This work not only shows the development potential of the WNG in low‐speed wind energy collection but also expends the application potential of TENG‐based self‐powered environmental monitoring.
As one of the few self-powered instruments and devices, triboelectric nanogenerators (TENGs) have been developed for more than 10 years since its invention in 2012. With wide material selections and diverse design structures, and without having to use an external power supply, TENG has been applied in many key technologies. By the end of 2022, more than 16,000 researchers from 83 countries and regions around the world have authored scientific papers in TENG. In this review, we start from the theoretical principles and working mechanisms of TENG, and discuss its 5 major fields of application, namely, as self-powered sensors, high-voltage energy devices, blue energy devices, micro/nano-energy devices, and solid–liquid interface probes. Next, we review the breakthrough progress made using TENG as commercial products in the following fields: medical health, intelligent security, and marine energy. Finally, we look forward to the future fields of application of TENG as advanced instruments and devices, especially in fluid dynamics sensing and aerospace fields. We firmly believe that various instruments and devices based on TENG technology will better serve the progress of human civilization.
