RESUMO
A novel microchannel heat sink (TFMCHS) with trapezoidal ribs and fan grooves was proposed, and the microchannel was manufactured using selective laser melting technology. Firstly, the temperature and pressure drop at different power levels were measured through experiments and then combined with numerical simulation to explore the complex flow characteristics within TFMCHSs and evaluate the comprehensive performance of microchannel heat sinks based on the thermal enhancement coefficient. The results show that, compared with rectangular microchannel heat sinks (RMCHSs), the average and maximum temperatures of TFMCHSs are significantly reduced, and the temperature distribution is more uniform. This is mainly caused by the periodic interruption and redevelopment of the velocity boundary layer and thermal boundary layer caused by ribs and grooves. And as the heating power increases, the TFMCHS has better heat dissipation performance. When P=33 W and the inlet flow rate is 32.5 mL/min, the thermal enhancement factor reaches 1.26.
RESUMO
All-inorganic cesium lead bromine (CsPbBr3) perovskites quantum dots (QDs) are one of the most photoelectric materials due to their high absorption coefficient, pronounced quantum-size effect, tunable optical property. Here, a self-powered PD based on all-inorganic CsPbBr3perovskites QDs is fabricated and demonstrated. The light-induced pyroelectric effect is utilized to modulate the optoelectronic processes without the external power supply. The working mechanism of the PD is carefully investigated upon 532 nm laser illumination and the minimum recognizable response time of the self-powered PD is 1.5µs, which are faster than those of most previously reported wurtzite nanostructure PDs. Meanwhile, the frequency and temperature independence of the self-powered PD are experimented and summarized. The self-powered PD with high performance is expected to have extensive applications in solar cell, energy harvesting, resistive random access memory.