We report the enhanced field emission of B-doped SiC nanowires with a low turn-on field and enhanced high-temperature stability.

Under 980 nm excitation, unusual 3P2-->3H6 (approximately 264 nm) and 3P2-->3F4 (approximately 309 nm) emissions from Tm3+ ions were observed in hexagonal NaYF4:Yb3+ (20%)/Tm3+ (1.5%) microcrystals. In comparison with the strong emissions from 1D2 and 1I6, the emissions from 1G4 and 3H4 almost vanished due to the efficient cross-relaxation of 1G4 + 3H4-->3F4 + 1D2(Tm3+). Double logarithmic plots of the upconversion emission intensity versus the excitation power are neither straight lines nor typical saturation curves. Theoretical analysis indicated that the complicated dependent relationships were mainly caused by phonon-assisted energy transfers and nonradiative relaxation.

Flexible porous Ti3C2Txdecorated rGO films with high volumetric capacitance were produced to eliminate the need for the delamination of MXenes.

Coplanar energy storage devices with interdigitated electrodes have attracted a significant amount of attention as micropower units for portable and flexible electronics, and self-powered systems. Herein, we propose a simple, cost-effective, and scalable two-step screen-printing process to fabricate flexible coplanar asymmetric microscale hybrid device (MHD) with a higher energy density compared to carbon-based microsupercapacitors. 2D titanium carbide MXene (Ti 3 C 2 T x) with a large inlayer spacing is selected as negative electrode, and CoAl layered double hydroxide (LDH) nanosheets are selected as positive electrode. The assembled coplanar, all-solid-state, asymmetric MHD possesses a higher energy density (8.84 μWh cm-2) compared to the MXene-based, coplanar, symmetric microsupercapacitors (3.38 μWh cm-2), and exhibit excellent flexibility and reliability, as well as cycling stability (92% retention of the initial capacitance after 10,000 cycles). Moreover, we integrate the coplanar asymmetric MHDs with the force sensing resistors as portable power source units to fabricate lightweight and inexpensive integrated force sensors, which can be used to detect applied pressure variation. The two-step screen-printing method can also be extended to other MXenes and various positive electrode materials for fabrication of coplanar asymmetric MHDs on flexible substrates. Therefore, we believe that the two-step screen-printing method opens up new avenues toward developing flexible coplanar asymmetric MHDs, thus promoting the application of MHDs based on MXenes for flexible integrated electronic devices.