High oxygen vacancy concentration produced by bismuth volatilization during the sintering process has become one of the most important obstacles for the practical applications of Bi₄Ti₃O₁₂ (BIT)-based high temperature piezoelectric ceramics. In this work, Cu and Sb were selected to modify the oxygen vacancy concentration and the electrical properties of the BIT ceramic. The crystal structure, microstructure, electrical conduction behaviors, and piezoelectric properties of Bi₄Ti_{3 − x}(Cu_1/3Sb_2/3)_xO₁₂ (BTCS) (x = 0, 0.01, 0.02, 0.03, 0.035, 0.04, and 0.05) ceramics were investigated in detail. Codoping significantly reduced the oxygen vacancy concentration and resulted in enhanced electrical resistivity along with improved piezoelectric properties. The BTCS ceramic with x = 0.035 exhibited optimized comprehensive performances such as a remarkable DC resistivity of 1.40 × 10⁷ Ω cm at 500 °C and a relatively large piezoelectric coefficient (24 pC/N). Furthermore, the ceramic also showed good thermal stability of the piezoelectric coefficient and an excellent fatigue behavior. These results demonstrate the great potentials of Cu/Sb codoped BIT ceramics for piezoelectric device applications at high temperatures up to 500 °C.

With the development of the economy, electricity demand continues to increase, and the time for electricity consumption is concentrated, which leads to increasing pressure on the voltage regulation of the distribution network. For example, a large number of electric vehicles charging during a low-price period may cause the problem of under-voltage of the distribution network. On the other hand, the penetration of distributed power generation of renewable energy may cause over-voltage problems in the distribution network. This study proposes a Stackelberg game model between the distribution system operator and the load aggregator. In the Stackelberg game model, the distribution system operator affects the users’ electricity consumption time by issuing subsidies to decrease the frequency of voltage violations. As the representative of users, the load aggregator helps the users schedule the demand during the subsidized period to maximize profits. Case studies are carried out on the IEEE 33-bus power distribution system. The results show that the time of the subsidy can be optimized based on the Stackelberg game model. Both the distribution system operator and the load aggregator can obtain the optimal economic profits and then comprehensively improve the operating reliability and economy of the power distribution system.

The high penetration of photovoltaic (PV) systems in low-voltage distribution networks relieves the pressure of energy shortages. However, the severe intermittency and variability in the output of PVs also bring a series of voltage quality problems, such as over-voltage, under-voltage, and voltage fluctuations. In this paper, a novel voltage control strategy based on air conditioners (ACs) and an on-load-tap-changer (OLTC) is proposed. By regulating the operating power of the ACs, voltage regulation powers are provided for the distribution network during the regulation time delays of the OLTC, which can effectively avoid the occurrence of regulation lag by the OLTC. The thermal model and electrical model are established to evaluate the operating performance of voltage regulation potential of the ACs. Furthermore, the voltage regulation strategy is formulated based on the regulation potential of the ACs, which it can make full use of. The effectiveness of the proposed voltage control strategy is illustrated in numerical studies.

The development of optoelectronic technologies demands photodetectors with miniaturization, broadband operation, high sensitivity, and low power consumption. Although 2D van der Waals (vdW) heterostructures are promising candidates due to their built-in electric fields, ultrafast photocarrier separation, and tunable bandgaps, defect states limit their performance. Therefore, the modulation of the optoelectronic properties in such heterostructures is imperative. Surface charge transfer doping (SCTD) has emerged as a promising strategy for non-destructive modulation of electronic and optoelectronic characteristics in two-dimensional materials. In this work, we demonstrate the construction of high-performance p−i−n vertical heterojunction photodetectors through SCTD of MoTe ₂ /ReS ₂ heterostructure using p-type F ₄ -TCNQ. Systematic characterization reveals that the interfacial doping process effectively amplifies the built-in electric field, enhancing photogenerated carrier separation efficiency. Compared to the pristine heterojunction device, the doped photodetector exhibits remarkable visible to near-infrared (635−1064 nm) performance. Particularly under 1064 nm illumination at zero bias, the device achieves a responsivity of 2.86 A/W and specific detectivity of 1.41 × 10 ¹² Jones. Notably, the external quantum efficiency reaches an exceptional value of 334% compared to the initial 11.5%, while maintaining ultrafast response characteristics with rise/fall times of 11.6/15.6 μ s. This work provides new insights into interface engineering through molecular doping for developing high-performance vdW optoelectronic devices.