Multiple Color Emission of Mechanoluminescence and Photoluminescence from SrZnSO: Bi3+ for Multimode Anticounterfeiting.

Mechanoluminescence materials that emit light under mechanical stimulation have attracted widespread attention in sensing, anticounterfeiting, and imaging applications. In this study, a series of Sr1-xBixZnSO (0.001 ≤ x ≤ 0.1) samples was synthesized by the method of high temperature solid-state reaction. It is worth noting that the distortion degree of the SrO3S3 octahedron was increased with increasing Bi3+ concentration, and the color manipulated Sr1-xBixZnSO which can emit different photoluminescence (blue to dark blue and finally red) and mechanoluminescence (orange to red) colors is obtained. Moreover, the deep traps can stably store and provide electronic supplements in shallow traps released under mechanical stimulation. Therefore, devices made of SrZnSO:Bi3+ phosphor and polydimethylsiloxane (PDMS) can be used as thermo-mechano-opto three-mode anticounterfeiting. The ML intensity is linear to the external load and can be utilized for stress sensing or imaging.

Efficient energy transfer from Bi3+ to Mn2+ in CaZnOS for WLED application.

A series of Bi3+ and Mn2+ co-doped CaZnOS phosphors with a tunable emission color have been synthesized by a high temperature solid-state reaction method. Their crystal structure, spectroscopic properties, energy transfer and thermal quenching have been investigated systematically. An intense blue-green emission band at 485 nm and a red emission band at 616 nm were observed at an excitation wavelength of 375 nm, owing to the 3P1,0→1S0 transition of Bi3+ and the 4T1(4G) →6A1(6S) transition of Mn2+, respectively. The tunable color from blue-green, white light to red light can be obtained by varying the Mn2+ ion concentration from 0.005 to 0.015 in CaZnOS:Bi3+. The decay time decreased from 642 to 273 ns with the Mn2+ ion concentration x increasing from 0.005 to 0.015, and the energy transfer efficiency ηT can reach up to 65% in the CaZnOS:Bi3+,0.015Mn2+ phosphor. As the temperature increases from 300 to 420 K, the emission intensity is maintained at 67%, and the activation energy Ea is estimated to be 0.28 eV. An LED fabricated using CaZnOS:Bi3+,0.01Mn2+ exhibited the chromaticity coordinates and corrected color temperature (CCT) of (0.338, 0.364) and 4655 K, respectively. These results validate the promising applications of the CaZnOS:Bi3+,Mn2+ phosphor in UV white LEDs.

Dendrite Integration Mimicked on Starch-Based Electrolyte-Gated Oxide Dendrite Transistors.

Emulation of dendrite integration on brain-inspired hardware devices is of great significance for neuromorphic engineering. Here, solution-processed starch-based electrolyte films are fabricated, demonstrating strong proton gating activities. Starch gated oxide dendrite transistors with multigates are fabricated, exhibiting good electrical performances. Most importantly, dendrite modulation, spatiotemporal dendrite integration, and linear/superlinear dendrite algorithm are demonstrated on the proposed dendrite transistor. Furthermore, a low energy consumption of ∼1.2 pJ is obtained for triggering a synaptic response on the dendrite transistor. Accordingly, the signal-to-noise ratio is still as high as ∼2.9, indicating a high sensitivity of ∼4.6 dB. Such artificial dendrite transistors have potential applications in brain-inspired neuromorphic platforms.