With the growing economy and technology, disease prevention and individual health are becoming more and more important. It is highly urgent to develop a non-toxic, self-powered, and safe high-voltage power source to prevent diseases spread by mosquitoes, especially in isolated or remote areas. Herein, we reported a high-performance rotary triboelectric nanogenerator (R-TENG) based on customized theoretical simulations and a ferroelectric nanocomposite intermediate layer. The customized theoretical simulations based on gradient electrode gaps were established to optimize gap angles and segment numbers of the electrodes, which could prevent air breakdown and enhance the R-TENG output energy by at least 1.5 times. Meanwhile, the electrical output performance of the TENG was further enhanced with a highly oriented BaTiO₃ (BTO) nanoparticles intermediate layer by about 2.5 times. The open-circuit voltage of R-TENG reached more than 6 kV and could continuously light 3420 light-emitting devices (LEDs) or 4 serially connected 36 W household fluorescent lamps. Therefore, a self-powered high-voltage disease prevention system is developed based on the high-performance R-TENG to reduce the risk of disease transmission. This work provides a prospective strategy for the further development of TENGs and expands practical applications of self-powered and high-voltage systems.

In spite of the explosive rise of research on memristive switching, more improvements in tunability, versatility, and hetero-integration are required through the discovery and application of novel materials. Herein, we report resistance switching in nano-thick two-dimensional (2D) crystals of bismuth selenium (BiSe). The BiSe devices exhibit nonvolatile bipolar resistance switching, volatile switching, and electrical bistable behavior in different conditions. The different memristive behavior of BiSe devices may be related to the concentration of Bi ions in this Bi-rich structure, which directly affects the capability of filaments forming. Furthermore, the external mechanical strain is applied in modulation of multi-layer BiSe devices. The memristive BiSe devices show a large on/off ratio of ~ 10⁴ and retention time of ~ 10⁴ s. The discovery of memristive switching behavior in multi-layer BiSe is attributed to the forming of Bi filaments. The resistance switching behavior in multi-layer BiSe demonstrates the potential application in the flexible memories and functional integrated devices.

Tin-lead (Sn-Pb) alloyed perovskites with tunable bandgaps hold great potential for constructing highly efficient single-junction and tandem photovoltaic devices. However, the efficiency and stability of Sn-Pb perovskite solar cells (PSCs) are greatly hampered by severe nonradiative recombination due to the easy oxidation of Sn(II). In this work, we report the construction of mixed dimensional two-dimensional (2D) Dion–Jacobson (DJ) and three-dimensional (3D) perovskites to improve the efficiency and stability of Sn-Pb alloyed PSCs. Introducing a small amount of 1,4-butanediammonium diiodide as spacer cations of DJ perovskites into precursor, the prepared mixed dimensional Sn-Pb alloyed perovskites exhibit reduced trap-state density due to the passivation of 2D DJ perovskites. As a result, nonradiative charge recombination is greatly suppressed. The prepared Sn-Pb alloyed PSCs based on 2D-DJ/3D heterojunction deliver a power conversion efficiency of 19.02% with an impressive fill factor of 80%. As well, improved device stability is realized due to the presence of DJ perovskites which serves as a protection barrier against oxidation and water invasion.

Mechanoluminescent materials that convert mechanical stimuli to light emission have attracted extensive attention for potential applications in human-machine interactions. Here, we report a simple and available novel approach for the oxygen-assisted preparation of ZnS: Mn particles by solid-state reaction at atmospheric pressure without the formation of the corresponding oxides. The existence of O₂ has a positive impact on the formation of S vacancies in wurtzite-phase ZnS, leading to the introduction of Mn²⁺ ion luminescent centers and shallow donor levels, which can improve the electron-hole recombination rate. The O₂ ratio and Mn²⁺ ion doping concentration have significant effects on the luminous efficiency, which is optimal at 1%–20% and 1 at.%–2 at.% respectively. In addition, a device based on the piezo-photonic effect with excellent pressure sensitivity of 0.032 MPa^-1 was fabricated, which can map the two-dimensional pressure distribution ranging from 2.2 to 40.6 MPa in situ. This device can be applied to real-time pressure mapping, smart sensor networks, high-level security systems, human-machine interfaces, and artificial skins.

Nanomaterials show promising opportunities to address clinical problems (such as insufficient capture of circulating tumor cells; CTCs) via the high surface area-to-volume ratio and high affinity for biological cells. However, how to apply these nanomaterials as a nano-bio interface in a microfluidic device for efficient CTC capture with high specificity remains a challenge. In the present work, we first found that a titanium dioxide (TiO₂) nanorod array that can be conveniently prepared on multiple kinds of substrates has high affinity for tumor cells. Then, the TiO₂ nanorod array was vertically grown on the surface of a microchannel with hexagonally patterned Si micropillars via a hydrothermal reaction, forming a new kind of a micro-nano 3D hierarchically structured microfluidic device. The vertically grown TiO₂ nanorod array was used as a sensitive nano-bio interface of this 3D hierarchically structured microfluidic device, which showed high efficiency of CTC capture (76.7% ± 7.1%) in an artificial whole-blood sample.

A novel infrared light emitting diode (LED) based on an ordered p-n heterojunction built of a p-Si_1–xGe_x alloy and n-ZnO nanowires has been developed. The electroluminescence (EL) emission of this LED is in the infrared range, which is dominated by the band gap of Si_1–xGe_x alloy. The EL wavelength variation of the LED shows a red shift, which increases with increasing mole fraction of Ge. With Ge mole fractions of 0.18, 0.23 and 0.29, the average EL wavelengths are around 1, 144, 1, 162 and 1, 185 nm, respectively. The observed magnitudes of the red shifts are consistent with theoretical calculations. Therefore, by modulating the mole fraction of Ge in the Si_1–xGe_x alloy, we can adjust the band gap of the SiGe film and tune the emission wavelength of the fabricated LED. Such an IR LED device may have great potential applications in optical communication, environmental monitoring and biological and medical analyses.

A ZnO micro/nanowire has been utilized to fabricate Schottky-contacted humidity sensors based on a metal–semiconductor–metal (M–S–M) structure. By means of the piezotronic effect, the signal level, sensitivity and sensing resolution of the humidity sensor were significantly enhanced when applying an external strain. Since a higher Schottky barrier markedly reduces the signal level, while a lower Schottky barrier decreases the sensor sensitivity due to increased ohmic transport, a 0.22% compressive strain was found to optimize the performance of the humidity sensor, with the largest responsivity being 1, 240%. The physical mechanism behind the observed mechanical–electrical behavior was carefully studied by using band structure diagrams. This work provides a promising way to significantly enhance the overall performance of a Schottky-contact structured micro/nanowire sensor.