With the high capacity brought by the external liquid tanks, fuel cells and flow cells have shown positive application prospects as power batteries and energy storage batteries, respectively. However, low power density and low volume energy density are the bottlenecks limiting their commercialization. Herein, a GaInSn-liquefied Zn-metal strategy has been proposed for developing high-performance room temperature aqueous liquid fuel cells and rechargeable flow cells. Among them, GaIn alloy was used to dissolve Zn metal, and Sn was used to improve the corrosion resistance of the liquid alloy. At room temperature, the developed liquid fuel cell exhibited a peak discharge power density of up to 78.792 mW cm- 2, good low-temperature start-up property, flexibility, and elasticity. Moreover, through the design of a dual circulation operating mode of liquid metal anode and electrolyte, the liquid metal-air flow cell showed stable discharging and charging performance for over 30 h at current densities of 25 mA cm- 2 and 15 mA cm- 2, respectively. The concept of "liquid reaction-solid energy storage" has been realized: the flowing anode enables real-time updating of metals and participates in electrochemical reactions in liquid phase; The external Zn metal immersed in saturated liquid metal achieves an increase in the volume energy density of the electrochemical cells in solid form.

Reversible metal electrodeposition (RME) dynamic windows with advantages of lowering buildings' carbon footprint and enhancing occupant comfort demonstrate significant potential in energy-efficient buildings. However, the accumulation of insoluble by-products during the reaction worsens cyclic reversibility. Herein, phosphorylcholine (PC) was added to the Cu-Bi electrolyte to facilitate rapid metal deposition/dissolution kinetics while simultaneously achieving a low driving-voltage and enhanced cyclic reversibility. Studies show that PC molecules can modulate the solvation structure of metal ions, thereby inhibiting side reactions related to H2O in the electrolyte. Meanwhile, activation energy gap (Delta Ea) between reduction and oxidation processes decreases from 2.96 to 0.19 kJ mol-1, indicating the rapid reaction kinetics and the inhibition of insoluble byproducts, which makes a significant improvement in the reversibility of chronoamperometric cycling (with 70% of the initial current density maintained after 3000 cycles). Lastly, RME devices undergo fast chromic transition at a low driving-voltage of-0.53 V, and RME powered by solar cells exhibit an optical contrast of 59.05% at 580 nm under 1-sunlight, respectively. These results demonstrate that the PC is a promising candidate for enhancing the performance of RME dynamic windows.

Aqueous zinc metal batteries (AZMBs) demonstrate compelling advantages of low cost, high safety, and environmental benignity, rendering them promising candidates for next-generation energy storage systems. However, their commercialization is impeded by irreversible Zn anode issues, including dendrite growth, interfacial corrosion, and parasitic side reactions. This work introduces sodium tartrate (NTA) as a dual-ion additive that mitigates these challenges via cationic (Na+) electrostatic shielding and anionic (TA2-) acceleration of [Zn(H2O)6]2+ desolvation, guiding uniform (002)-oriented Zn deposition. Such a deposition orientation facilitates the uniform nucleation of Zn2+ on the Zn anode. Leveraging the synergistic adsorption protection of Na+ and TA2-, this mechanism ultimately enables a highly reversible Zn anode. Results confirm the Zn symmetric cell with modified electrolyte achieves stable reversible Zn plating/stripping for over 3000 h at 6.0 mA cm-2/1.0 mAh cm-2. Moreover, the Zn||Cu asymmetric cell exhibits exceptional cycling stability, delivering an average coulombic efficiency (CE) of 99.81% over 2900 cycles at 1.0 mA cm-2/0.5 mAh cm-2 and 99.82% over 3000 cycles at 5.0 mA cm-2/1.0 mAh cm-2. The NTA additive also demonstrates outstanding electrochemical compatibility in both Zn||alpha-MnO2 and Zn||I2 full cells. Notably, the Zn||I2 full cell maintains a high capacity retention of 93.29% after 10 000 cycles at 5.0 A g-1, highlighting its practical potential.

In this work, we report the 64-channel high-power evanescent quantum dot laser arrays with 100 GHz channel spacing. The structure of laser arrays is optimized by the coupled mode theory and eigenmode expansion method. The simulation results show that the sampling period of laser units is in the range of 2724-4377 nm with the period of seed gratings fixed at 210 nm, the corresponding +1st-order lasing wavelength is in the range of 1291.88-1327.79 nm, and the channel spacing of the adjacent laser units is 0.57 nm. Meanwhile, the error tolerance of the fabrication process is largely relaxed by about 292 times compared to the conventional distributed feedback grating. In addition, the asymmetric sampled Bragg grating is adopted to improve the output power from one side of laser units. Compared to the conventional symmetric sampled Bragg gratings, the asymmetric sampled Bragg gratings increases the ratio of the output power from both sides of laser units from 1.0 to a maximum of 2.1 by optimizing lambda /4 phase-shift position and sampling duty cycle. This work provides a feasible solution for the fabrication of multi-channel evanescent quantum dot laser arrays with narrow channel spacing and further promotes the application of silicon photonic chips.

Reversible metal electrodeposition devices (RMEDs) powered by solar cells have shown promising prospects in energy-saving buildings, whereas the high driving-voltage and unclear nucleation/growth mechanism of metal particles have hindered their...

In this paper, we design an adaptive method to fabricate electrically pumped microring lasers with a narrow ring width. We fabricated electrically pumped microring lasers with ring widths ranging from 3 to 8 μm using optical lithography. Under continuous-wave (CW) condition at room temperature, a 650nm band microring laser with a radius of 20 μm and ring width of 3 μm demonstrated a threshold current density of 5.2 kA/cm2 and a differential resistance of 20 Ω. Experimental results show that adaptive lithography has the potential for low-cost and large-scale production of microring lasers with high optical quality.

Carbon dots have been extensively studied as a -stable, tunable, and environmentally friendly light-emitting material in light-emitting diodes. However, it has been found that no matter how the properties of carbon dots (CDs) are optimized, the device performance is still unsatisfactory, and even solid-state CDs with high quantum yields do not necessarily imply better device performance. In this study, CDs are doped into host materials- to form an emissive layer. When excited by an applied electric field, the CDs act as luminescent guest molecules, while the host material provides the desired charge transport properties and stability. This method- improves the morphology of the emissive layer and balances the charge transport and distribution, thus increasing the charge compounding efficiency and improving the device performance, with poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] as the hole transport layer and 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene as the host material doped with CDs, the luminance is as high as 9754 cd m-2 and the efficiency is 8.53 cd A-1. The results of the study show that in addition to the synthesis of highly efficient solid-state fluorescent CDs, the design of the device structure and the development of more efficient hole-transporting materials are also key factors to improve the performance of CDs-based light-emitting diodes.

Reducing the energy consumption of CO2 regeneration is crucial for enhancing the economic feasibility of CO2 capture processes. While most studies have focused on developing novel absorbents, the influence of operating parameters on gas-liquid mass transfer behavior and their subsequent impact on energy consumption has received limited attention. This study experimentally investigates the regeneration heat duty (Qreg) for CO2 desorption from a 1-(Dimethylamino)-2-propanol (1DMA2P)/2-Methylaminoethanol (MAE) aqueous blend in a lab-scale stripper equipped with high-efficiency Sulzer DX structured packing. The effects of key operating parameters, including rich CO2 loading, lean CO2 loading, solution flow rate, amine concentration, and synergistic parameters (Delta alpha x L and C x L), on Qreg were systematically analyzed. The experimental results showed that all these factors greatly influenced Qreg. For example, the Qreg decreases as the lean CO2 loading (alpha lean), rich CO2 loading (alpha rich), and 1DMA2P/MAE concentration (C) increase, indicating that the Qreg can be reduced by optimizing these operating parameters. Additionally, compared with MEA, 1DMA2P/MAE reduces energy consumption by 51.5 % and decreases the stripper height by 35 %. This study underscores the critical role of operating parameters in reducing CO2 regeneration energy consumption. The findings provide valuable insights into optimizing stripper performance and demonstrate the advantages of the 1DMA2P/MAE blend as an energy-efficient alternative to MEA-based solvents in industrial CO2 capture applications.

Great achievements in the bonded III-V lasers have pushed the productization process of silicon photonic chips. In this work, we report the design of silicon evanescent lasers with asymmetric gratings, which can provide high output power and stable single-longitudinal-mode operation. The high coupling efficiency and low threshold current density are achieved by linearly expanding the width of rib waveguide from 0.4 mu m to 2 mu m through 150 mu m taper coupler. By optimizing the lambda/4 phase-shift position ratio from conventional 0.50 to 0.64, the ratio of output power at both sides of the bonded lasers (P2/P1) is improved from1.0 to 5.0, and the normalized grating coupling coefficient (kappa L) remains at 2.78. By optimizing the duty cycle at one side of lambda/4 phase-shift from 0.5 to 0.8 and another side remains at 0.5, P2/P1 is 3.3, and kappa L lowers from 2.78 to 2.21. Besides, keeping the phaseshift position ratio at 0.64 while changing the duty cycle to 0.7, P2/P1 increases significantly to 7.5 with kappa L of 2.59. This work provides a step forward towards the development of high-power silicon-based light sources.

The multi-wavelength laser array is crucial for high-capacity silicon photonic systems based on (dense) wavelength division multiplexing technology. However, realizing 8-wavelength or more laser arrays is challenging solely by adjusting the grating period due to the large wavelength spacings of about 12–20 nm. In this letter, we report a 16-wavelength heterogeneously integrated quantum dot distributed feedback laser array with varying silicon waveguide width and grating period. The effective refractive index of gratings is calculated by eigenmode expansion method. Considering the power reflectivity, normalized coupling coefficient and manufacturing process of gratings, the etch depth and duty cycle of gratings are optimized to 10 nm and 0.8, respectively. When the grating period is fixed at 198 nm and the silicon waveguide widths are 560 nm, 590 nm, 615 nm, and 635 nm, respectively, the corresponding lasing wavelengths are 1310.72 nm, 1311.26 nm, 1311.80 nm, and 1312.31 nm, respectively, and the wavelength spacing of adjacent laser units is about 100 GHz (0.57 nm). Furthermore, by adjusting the grating period between 196 and 202 nm with 2 nm spacing of grating period, the number of lasing wavelengths is increased to 16, and the range of lasing wavelengths is broadened to 1298.03–1337.44 nm. This work provides an excellent solution for realizing multi-wavelength heterogeneously integrated III-V/Si distributed feedback laser arrays and expanding the number of wavelengths, thereby advancing the development of high-capacity silicon photonic systems.

Perovskite light-emitting diodes (PeLEDs) have gained significant attention owing to their remarkable tunability and color stability, and substantial progress has been made with green and red PeLEDs. However, the advancement of blue PeLEDs still lags far behind their red and green counterparts. In this study, we report efficient sky-blue PeLEDs utilizing an in situ fabricated CsPb2Br5 plates/quasi-2D perovskite heterojunction using chelating molecules to modulate the crystallization process of perovskites. The wide bandgap of CsPb2Br5 facilitated the formation of a type-I band alignment at the heterojunction, allowing efficient carrier transfer from CsPb2Br5 to CsPbBr3. This heterojunction leads to a noteworthy enhancement of device efficiency. The PeLEDs exhibit a maximum brightness of 2311 cd m-2, accompanied by a maximum external quantum efficiency of 12.86% at 487 nm. Our tailored design of CsPb2Br5/perovskite heterojunction thin films offers a promising avenue for advancing PeLED performance. This work contributes valuable insights into the burgeoning field of perovskite electroluminescence, paving the way for further optimization of PeLED technologies.

Multi-wavelength light sources are crucial for high-bandwidth silicon photonic chips. In this paper, a single heterogeneous quantum dot distributed feedback (DFB) laser emitting 4 wavelengths using the combination-grating technology is designed. To the best of the knowledge, this is the first heterogeneously integrated quantum dot DFB laser that lases stable multi-wavelength in a single cavity. When the etching depth, etching width, and total length of gratings are 100 , 550 nm, and 1 000 mu m, respectively, 4-wavelength with 1297.01 , 1303.38 , 1309.74 , and 1316.11 nm are obtained by varying the grating period from 196 to 199 nm with the spacing of 1 nm. Compared to the conventional DFB laser arrays, the DFB laser units are significantly reduced by 3/4 while maintaining the same number of output wavelengths. Additionally, by optimizing the lambda/4 phase-shift position and the duty cycle of gratings, the output power at the front-end of the 4-wavelength laser is significantly improved. Specifically, the ratio of the output power from the front-end and rear-end of the laser increases from the conventional 1.00 to 2.51. This work provides a competitive candidate for multi-wavelength, high-performance, and large-scale silicon-based light sources used in data centers, lidar, and component detection. 1.3 mu m band single 4-wavelength heterogeneously integrated quantum dot distributed feedback lasers are first designed. 4-wavelength lasing is realized by introducing 4-period gratings in a single cavity. Additionally, by adopting asymmetric gratings, the ratio of the output power from the front-end and rear-end of the laser increases from the conventional 1.00 to 2.51. image

We report electrically pumped continuous-wave (CW) InAs/GaAs quantum dot lasers monolithically grown on planar on-axis Si (001) substrates. Combining an asymmetric waveguide epitaxy structure with aluminium-free upper cladding layers and a symmetrical cathode chip structure, 1.3 mu m band lasers with low differential resistance and high slope-efficiency have been achieved. Moreover, the optimized symmetrical cathode structure of the laser chips is used to improve the slope-efficiency by reducing the differential resistance and waste heat. The Fabry-Perot broad-stripe edge-emitting lasers with 2000 mu m cavity length and 15 mu m stripe width achieve a single-facet output power of 73 mW, a single-facet slope efficiency of 0.165 W A(-1), and a differential resistance of 1.31 Omega at similar to 1.31 mu m wavelength under CW conditions at room temperature (25(degrees)C). Importantly, these results provide an effective strategy to achieve 1.3 mu m wavelength band single-mode distributed feedback lasers directly on planar on-axis Si (001) substrates with high efficiency.

Blue perovskite light-emitting diodes (PeLEDs) based on pure bromide compositions exhibit notable potential attributed to their stable performance and the absence of halogen phase separation. Nevertheless, a considerable challenge persists in the effective suppression of narrow-bandgap emission phases to ensure optimal color purity. In this investigation, we delve into the utilization of zwitterionic β-alanine (β-Ala) to facilitate the formation of nanocrystalline-structured perovskite. β-Ala, possessing both amino and carboxyl groups, is an effective passivating agent for various defect sites on the perovskite's surface, exhibiting versatility through multiple binding modes. This irregular passivation pattern strategically hinders the perovskite from adopting a conventional quasi-2D layered structure. Through the strategic implementation of diamine ligands and CsBr to modulate the growth process, we successfully engineered quasi-2D perovskite nanocrystals with Dion–Jacobson phase (Q-2D PNCs) via an in situ coordination process. The application of the PNCs as emitters in blue PeLEDs yielded promising outcomes. The pure blue PeLED with electroluminescent peak at 473 nm achieves a maximum brightness and external quantum efficiency (EQE) of 8005 cd/m2 and 8.91%, respectively. Additionally, PeLEDs with sky blue emission (479 nm) exhibited a maximum brightness and EQE of 9431 cd/m2 and 10.02%, respectively.

Great advancements in III-V/Si epitaxy have pushed quantum dot lasers to the forefront of silicon photonics. In this work, we designed the structures of evanescent coupled quantum dot distributed feedback lasers with asymmetric gratings, which made significant improvement in on-chip output power while maintaining single-longitudinal-mode stability. The optimal lambda/4 phase-shift position (the ratio of the grating length from the rear-end of lambda/4 phase-shift to the total grating length) from conventional position of 0.50 to 0.64 allows the ratio of the output power at both sides of silicon waveguide to be increased from 1.0 to 5.9. Moreover, the optimal duty cycle at one side of the phase-shift from 0.50 to 0.8 allows the ratio to be increased from 1.0 to 3.7. Meanwhile, the ratio could be dramatically improved from 1.0 to 9.2 by changed the duty cycle at one side of phase-shift to 0.7 while maintaining the phase-shift position of 0.64. With those designed structures, evanescent coupled quantum dot lasers could challenge the state-of-the-art bonded quantum well lasers and may eventually become ubiquitous and affordable for future commercial production.

Integrated electrochromic devices powered by photovoltaic cells have evoked a lot of interest due to their promising commercial prospects. However, their application has been restricted by the voltage adaption between the self‐powered voltage and the color‐changing threshold voltage (Vt). Herein, a strategy of bidirectional voltage regulating is proposed to develop a novel stand‐alone integrated photovoltachromic device (I‐PVCD), which integrates perovskite/organic tandem solar cells (P/O‐TSCs) to drive color‐changing process of conjugated poly(3‐hexylthiophene) (P3HT) films. To lower the driving‐voltage of electrochromic layer, C60 is introduced to decrease the onset oxidation potential of P3HT film, and thus leading to a reduced Vt of 0.70 V benefiting from the enhanced highest occupied molecular orbital level and decreased charge transfer resistance from 67.46 to 49.89 Ω. Simultaneously, PBDB‐T is utilized as the hole transport layer in the interconnecting layer of CsPbI2Br/PTB7‐Th:IEICO‐4F P/O‐TSC to improve its open‐circuit voltage (Voc) to 1.85 V. Under their synergetic merits, a I‐PVCD with a wider self‐adaptive voltage range is achieved. This device can undergo fast and reversible chromic transition from beautiful magenta to transparent only under the solar radiation, and demonstrates a coloration efficiency of 351.90 cm2 C−1 and a switching time of 2 s besides its excellent operating reliability.

While the metal to insulator transition (MIT) of d-band correlated perovskite nickelates (RENiO3) are widely adjustable via their rare-earth composition, the roles of potential valence variabilities associated with the rare-earth elements were rarely concerned. Herein, we demonstrate the material synthesis and MIT properties of RENiO3 containing valence variable rare-earth compositions, such as Ce, Pr, Sm, Eu and Tb. The metastable perovskite structure of SmNiO3 and EuNiO3 with a rare-earth valence states variable towards +2 can be effectively synthesized under high oxygen pressures as it is necessary to reduce their formation free energies. This is in contrast to Ce and Tb, in which situations the variable rare-earth valence state towards +4 reduces their ionic radius and prohibits their occupation or co-occupation of the rare-earth site within the perovskite structured RENiO3. Nevertheless, PrNiO3 with MIT properties can be effectively synthesized at lower oxygen pressures, owing to the higher stability to form a fully occupied 6s orbit associated Pr3+ compared to the half-filled one related to Pr4+. The present work provides guidance for regulating the MIT properties of RENiO3.

Multi-wavelength laser array is currently one of the most attractive technologies to provide high density links for advanced optical communications and computing. The conventional scheme of varying grating period is almost impossible to achieve 8-wavelength or more. And, the optical output power of heterogeneously integrated quantum dot laser can hardly meet the commercial demand. In this paper, we report a 16-wavelength highpower heterogeneously integrated quantum dot distributed feedback laser array. To the best of our knowledge, this is the first heterogeneously integrated quantum dot laser array that tunes the lasing wavelength by combining the scheme of varying the stripe width and grating period of laser units. The effective refractive index of gratings is calculated by eigenmode expansion method. When the grating period is fixed at 198 nm, and the stripe widths of laser units are 2.00 mu m, 2.25 mu m, 2.60 mu m and 3.15 mu m, respectively, the corresponding lasing wavelengths are 1307.94 nm, 1308.49 nm, 1309.06 nm and 1309.63 nm, respectively, and the wavelength spacing of the adjacent laser units is about 100 GHz. By additionally adjusting the grating period between 196 nm and 202 nm with 2 nm spacing of grating period, a 16-wavelength QD DFB laser array is designed with the wavelength range from 1294.73 nm to 1336.09 nm. In addition, asymmetric distributed feedback grating is adopted to improve the optical output power at the front-end of laser arrays. The maximum ratio of the output power at the both end of laser units is 19.6 when the grating duty cycles of the front-end and the back-end of the lambda/4 phase-shift is 0.7 and 0.5, respectively, and the grating lengths is 250 mu m and 450 mu m, respectively. This work will promote the performance improvement of heterogeneously integrated quantum dot lasers and develop the quantum dot lasers towards multi-wavelength.

Herein, we report the phase transformation mechanism of the nominal Si(001) surface driven by hydrogen thermal annealing. The surface energies of H-terminated Si(001) surface with different phase structures were calculated by density functional theory. The results show that the surface phase with monoatomic steps can transform into the surface phase with diatomic steps under proper ranges of hydrogen chemical potential. Combining thermodynamic and kinetic factors, the phase transformation can't occur when annealing temperature lower or higher than 800 degrees C. In addition, surface phases with different types of diatomic steps are alternately transformed through the intermediate phase with monoatomic steps and the imperfection of the transformation process gradually increases with the extension of annealing time. Finally, different experiments have been carried and the experimental results are in good agreement with the phase transformation mechanism. This study provides complete theoretical mechanism and process parameters for controlling the phase structures of the nominal Si(001) surface through hydrogen thermal annealing.

Distributed photovoltaics in living environment harvest the sunlight in different incident angles throughout the day. The development of planer solar cells with large light-receiving angle can reduce the requirements in installation form factor and is therefore urgently required. Here, thin film organic photovoltaics with nano-sized phase separation integrated in micro-sized surface topology is demonstrated as an ideal solution to proposed applications. All-polymer solar cells, by means of a newly developed sequential processing, show large magnitude hierarchical morphology with facilitated exciton-to-carrier conversion. The nano fibrilar donor-acceptor network and micron-scale optical field trapping structure in combination contributes to an efficiency of 19.06% (certified 18.59%), which is the highest value to date for all-polymer solar cells. Furthermore, the micron-sized surface topology also contributes to a large light-receiving angle. A 30% improvement of power gain is achieved for the hierarchical morphology comparing to the flat-morphology devices. These inspiring results show that all-polymer solar cell with hierarchical features are particularly suitable for the commercial applications of distributed photovoltaics due to its low installation requirement.