An ultrathin CeO2 intermediate layer was introduced at the hetero-interface between the p-type Cu2ZnSnS4 (CZTS) absorber and the n-type CdS buffer to enhance carrier collection and overall device performance by hindering hole tunneling in kesterite thin-film solar cells. The CeO2 layer was deposited by chemical bath deposition and pulsed laser deposition (PLD), and the impact of these deposition methods on the structural and compositional properties was systematically investigated. XPS and SEM/EDX analyses revealed that PLD suppresses Ce2O3 formation and enables precise control of the thickness of the CeO2 layer. The optimized (<5 nm) CeO2 interlayer was integrated into two different solar cell architectures: monograin layer solar cells and thin-film solar cells, resulting in enhanced device performance. The power conversion efficiency increased from 7.1% to 9.0% for monograin layer cells and from 4.5% to 6.7% for thin-film devices.
Decarbonizing thermal management systems is essential for achieving global climate goals. Using radiative cooling (RC) combined with phase change material (PCM) represents an alternative approach towards achieving energy-neutral temperature control. Nevertheless, the typical RC-PCM solutions depend on fixed structures that are characterized by a lack of flexibility in structure which leads to thermodynamic and kinetic limitations. The solution to such system mismatches requires switching between passive temperature buffering and active, adaptive regulation strategies. This review not only focuses on traditional material optimization but also examines the latest advances in dynamical thermal management systems. It discusses how stimuli-responsive materials such as vanadium dioxide (VO2) enable real-time adjustment of optical properties and what components like heat pipes or microfluidic systems could provide an efficient heat transfer mechanism to manage heat exchange routes. It evaluates the usefulness of these adaptive structures in various situations (building envelopes, photovoltaic modules and wearable devices) when they are exposed to non-stationary thermal loads. Lastly, it provides a pathway to future development, where AI-enabled design can be used as an enabler of creating self-sustaining thermal control systems that are intelligent.
High temperature ceramics are used in a variety of harsh environments due to their mechanical strength and thermal stability. However, applications requiring high emissivity and/or absorptivity typically rely on “dark” ceramics, such as carbides, which are often expensive and complex to manufacture. In this work, a nanosecond pulsed laser is used to texture the surface of alumina, drastically increasing its emissivity in the near- and mid-infrared regions to levels comparable to those of silicon carbide. Emissivity was determined from reflectivity and transmissivity measurements at room temperature, and these measurements were used to estimate a hemispherical emissivity of up to 0.9 at 1000 °C, comparable to that of intrinsically “dark” ceramics such as graphite and silicon carbide. This technique offers a rapid and cost-effective method for enhancing the emissivity of alumina, thereby expanding its potential for applications requiring increased thermal radiation or absorption, such as emitters for thermophotovoltaic systems or absorbers in concentrated solar technologies.
Reducing active area loss at the wafer edge is an effective but difficult approach for increasing the efficiency of industrial silicon heterojunction (SHJ) solar cells. The difficulty lies in the fact that full-area ITO deposition inevitably leads to edge shunting, caused by wrap around during PVD processes. This study proposes a novel process route to eliminate SHJ cell shunting at the wafer edge caused by full-area PVD deposition. The process uses a HCl-based wet etchant to remove the ITO films wrap-around on the wafer edge, while the ITO films on the wafer surfaces are protected by screen-printed photoresist films that are originally used for grid patterning in copper plating. The approach requires no extra masking step. It can be easily integrated into the existing production lines with only minor modifications on the PVD carriers, enabling full-area ITO deposition on the rear side. With the help of full-area deposition on the rear side of the wafers, the cell efficiency significantly increases compared with reference samples that do not have full-area rear side ITO coverage. The new method increases JSC by 0.32 mA/cm2 and FF by 0.13% (absolute). Consequently, the highest average batch efficiency reaches 26.39%, a gain of 0.25% (absolute) over the reference.
Nickel oxide (NiOx) is a promising hole-transport layer for inverted perovskite solar cells, yet solution-processed NiOx can suffer from morphological inhomogeneity and interfacial defects that limit device performance. Here, we report a chemically regulated chemical bath deposition (CBD) strategy in which an intermediate oxalic acid (OA) treatment is introduced between precursor growth and thermal conversion. During CBD, ammonia-citrate coordination moderates Ni2+ hydrolysis and promotes the formation of a continuous Ni(OH)2 precursor film. Subsequent OA treatment reorganizes the loosely stacked nanosheet-like precursor surface, as supported by comparative spectroscopic and morphological analyses, and thermal annealing converts the modified precursor into a smooth and compact NiO film with a Ni2+-dominated, NiO-like surface composition. The resulting NiO/SAM stack supports more uniform perovskite film formation and reduced buried-interface non-radiative loss, as evidenced by steady-state PL, TRPL, DLCP, and device-level TPV measurements. Wide-bandgap inverted perovskite solar cells employing the optimized OA-treated CBD-NiO achieve a champion power conversion efficiency of 20.04% with an open-circuit voltage of 1.313 V. The devices also exhibit improved reproducibility and operational stability, retaining 87.0% of their initial PCE after 509 h of continuous MPPT under the specified laboratory conditions. These results demonstrate that intermediate precursor regulation is an effective approach for improving CBD-derived NiO hole-transport layers and their buried interfaces.
Current matching poses a critical challenge in developing high-efficiency all-perovskite tandem solar cells with two terminals. In this work,we present a numerical simulation of a novel three-terminal (3-T) back-contact all-perovskite tandem solar cell is presented featuring subcells with a back-contact light confinement (BCLC) structure. The BCLC design significantly enhances carrier generation and improves light utilization within the device, leading to a notable increase in efficiency. The power conversion efficiency (PCE) of the proposed device approaches 33%, representing a 1.3% absolute improvement over conventional 3-T back-contact all-perovskite tandem solar cells. Furthermore, incorporating BCLC structures into both the top and bottom cells results in a further improvement in PCE, exceeding 34%. The optical and electrical characteristics of these 3-T back-contact all-perovskite tandem solar cells are systematically analyzed, revealing the significant impact of the BCLC design on performance. The study also investigates the impact of varying BCLC geometrical parameters and the relative positioning of the BCLCs in the top and bottom cells on the performance of 3-T BCLC all-perovskite tandem solar cells. This work pioneers new architectures to fabricate high-efficiency all-perovskite tandem solar cells.
A self-powered photoelectrochromic device (PECD) is constructed using a TiO2/CdS/InP3 photoanode paired with a CuBi2O4/Nb2O5 electrochromic photocathode and a Na + -conducting redox-active gel electrolyte. The co-sensitized photoanode effectively suppresses recombination, exhibiting a prolonged back-electron-transfer time of ∼9 ms, a shortened excited-state electron lifetime of 0.4 ns, and a reduced electron-transport resistance of 115 Ω cm2. These synergistic improvements enable a power conversion efficiency of 5.9%, representing 1.5- and 4.7-fold enhancements over CdS-only and InP3-only cells, respectively. The well-aligned energy levels facilitate rapid injection of photogenerated electrons from the photoanode into the Nb2O5 layer, which undergoes a Nb5+/Nb4+ transition to produce a deep, uniform blue-black coloration and modulate incident solar radiation. Within the composite photocathode, the porous CuBi2O4 layer promotes uniform Na + influx from the electrolyte, enabling NaxNb2O5 formation, while simultaneously supplying electrons and delivering strong electrocatalytic activity for sulfide reduction at the photocathode/electrolyte interface. These functions are further supported by its longer carrier lifetime and reduced charge-transfer resistance relative to sole CuBi2O4. The resulting TiO2/CdS/InP3/gel/CuBi2O4/Nb2O5 PECD achieves an integrated visible-light modulation of 42.5%, rapid color–bleach switching within a few seconds between pale-yellow and blue-black states, a photocoloration efficiency of ∼47 W−1 cm2 min−1, and a coloration efficiency of ∼81.6 cm2 C−1 at 650 nm. This device marks a notable advance for PECDs, a field traditionally dominated by WO3 coupled with dye- or perovskite-based photoactive systems.
Improving dye regeneration and electron injection to the TiO2 conduction band remains a primary challenge in Dye-Sensitized Solar Cells (DSSCs). While co-adsorbents emerged as one of the key strategies to enhance dye binding, reduce aggregation, and passivate the photoanode surface, their behaviour in the TiO2 nanotube (TNT)-based system remains largely unexplored. This study investigates the effect of phenyl alkanoic acid (PAA) co-adsorbents with varying alkyl chain length on N719-sensitized TNT DSSCs. Co-adsorption effects were characterized through AFM, FTIR, Raman, UV–Vis DRS, and electrochemical analyses, complemented by DFT and TDDFT calculations to gain molecular-level insights into adsorption affinity, electronic structure modulation, and co-adsorbent interaction. Results demonstrate that PAA additions reduce dye aggregation and enhanced recombination resistance (RCt), with effects depending on alkyl chain length. The device performance hinges on balancing interfacial effects with dye loading and charge transport. Short-chain PAA (3PPA) promoted stronger passivation but significantly reduced dye loading due to competitive surface binding. Conversely, longer-chain PAAs introduced greater steric hindrance, restricting dye access to the TNT surface and lowered dye adsorption. Notably, 5PVA achieved the highest efficiency, outperforming the control by 42% under one-sun and 124% under low-light conditions. This success is attributed to an optimal balance between effective passivation and minimal dye displacement, as suggested by computational results. Stability test confirmed that 5PVA-modified devices retained performance better than the control. This work highlights the potential of PAA co-adsorbents to enhance the efficiency and durability of TNT/N719 DSSCs, offering pathways for optimization through molecular design and interfacial engineering.
The thermal characteristics and physical behaviors of MXene nanofluids are significantly superior compared to conventional heat transfer fluids, and thus have tremendous capacity for improving and advancing all forms of thermal systems. Out of all emerging types of advanced nanomaterials, MXenes (metal carbides, nitrides, and carbonitrides) have received great attention because of their extremely high thermal conductivity, thereby making them great candidates for the next generation of heat transfer applications when mixed uniformly throughout an appropriate base fluid. MXene nanoparticles will substantially improve both the effective thermal conductivity and overall heat transfer performance of nanofluids. This review will outline recent advancements in synthesis methods for MXenes, the formulation of nanofluids containing MXenes, and the performance evaluation of these MXene-based nanofluids. A comprehensive overview of these three categories will include descriptions of synthesis methods, methods for achieving uniform dispersion, as well as characterization techniques and how they affect the thermal and physical properties of nanofluids. Particular emphasis will be given to understanding the contributions of intrinsic properties of MXene nanoparticles to enhanced heat transfer performance. Additionally, research gaps will be identified, and important challenges to the development of MXenes and MXene-based nanofluids, such as dispersion stability, durability, and large-scale manufacture, will be discussed. In conclusion, because of their unique properties, MXene-based nanofluids are an exciting prospect for efficient thermal management systems. This review offers insightful information to help advance research and development in applications of MXene-based nanofluids for solar thermal and energy applications.
Integrating carbon capture with solar energy storage offers a promising pathway toward carbon neutrality, yet the synergistic utilization of carbonaceous materials from capture processes remains underexplored. Herein, we fabricate a flexible phase change film (PCF) using porous carbon derived from the reciprocal carbon–carbonate co-calcination (RCCC) of bamboo biochar and limestone. During RCCC, 93.2% of CO2 released from limestone is converted to CO. The optimized PCF composed of BC, thermoplastic polyurethane, and microencapsulated eicosane achieves a phase change enthalpy of 123.87 J g−1, excellent leakage-proof and mechanical stability. The photothermal conversion efficiency can reach 85.5%. This work demonstrates the first integration of RCCC-based carbon capture with flexible photothermal energy storage, offering a viable route for upgrading captured carbon into functional solar-thermal materials.
Parasitic absorption and transport loss of front contact remain key constraints for silicon heterojunction (SHJ) solar cells. Here, the properties of n-type hydrogenated nanocrystalline silicon oxide (n-nc-SiOx: H) films were controlled by regulating phosphine (PH3), carbon dioxide (CO2), and hydrogen (H2) flow rates during plasma-enhanced chemical vapor deposition. Subsequently, a single n-nc-SiOx: H layer was employed as the window layer in SHJ solar cells, achieving an efficiency of 21.37%. Although increasing the H2 flow rate improves both the transmittance and conductivity of n-nc-SiOx: H, it can also induce severe plasma damage to substrate, leading to a reduction in open-circuit voltage. To overcome this trade-off, a double window layer n1-nc-SiOx: H/n2-nc-SiOx: H was developed. The inner n1 layer protects the n-nc-Si: H seed layer and passivation layer, while the outer n2 layer provides lower refractive index and higher conductivity. This stack structure improves optical coupling and carrier transport. Compared with the single-layer reference, the double-layer SHJ cell increased efficiency from 21.37% to 22.04% (0.75 cm2) and further raised the efficiency of 210 mm × 105 mm industrial cells from 25.78% to 26.20%.
The development of efficient, lead-free semiconductors with tunable electronic and optical properties is essential for next-generation photovoltaic and optoelectronic technologies. Antiperovskites have recently attracted considerable attention owing to their structural versatility and compositional flexibility; however, Sb-based halide antiperovskites remain largely underexplored, with only limited studies available for selected compositions. In this work, first-principles density functional theory calculations are employed to systematically investigate the structural, vibrational, electronic, optical, and photovoltaic properties of cubic A3SbX3 (A = Mg, Ca, Sr; X = F, I) antiperovskites, providing a comprehensive comparative assessment of this material family. The optimized structures exhibit favorable energetic stability, while phonon dispersion calculations confirm their dynamical stability. The calculated electronic band structures reveal direct band-gap semiconducting behavior with band gaps spanning the visible to ultraviolet regions, demonstrating systematic tunability through cation and halogen substitution. Optical calculations predict strong absorption coefficients, enhanced dielectric responses, and favorable refractive indices, highlighting the iodide compounds for visible-light harvesting and the fluoride compounds for ultraviolet optoelectronic applications. Electron and hole effective mass analyses indicate comparatively favorable carrier transport in Sr3SbI3 and Sr3SbF3. Furthermore, Shockley–Queisser analysis predicts maximum theoretical power conversion efficiencies of 32.69% for Sr3SbI3, 28.99% for Sr3SbF3, and 18.61% for Ca3SbF3, whereas the narrow band gap of Mg3SbI3 suggests greater potential for narrow-gap optoelectronic devices than single-junction solar cells. These findings establish composition–property relationships within the A3SbX3 family and provide a robust theoretical framework for the development of lead-free antiperovskites for future photovoltaic and optoelectronic applications.
Inverted p-i-n perovskite solar cells (PSCs) have drastically increased in efficiency in recent years, partially due to the inclusion of self-assembling molecules (SAMs) as hole transporting materials (HTLs) and the addition of large organic ammonium salts as a passivating interlayer. In this study, the effect of halogen-functionalized carbazole-based ammonium salts as interlayers between the perovskite absorber and different HTLs is investigated. Fluorinated (F2-Cz), chlorinated (Cl2-Cz), and brominated (Br2-Cz) derivatives are synthesized and incorporated into p-i-n PSCs using NiOx, PTAA, 2PACz, and 4PAPyr as HTLs. All interlayers improve the open-circuit voltage (Voc), indicating effective defect passivation. Notably, a systematic increase in current density (Jsc) and overall PCE is observed across the halogen series from fluorine to bromine. Br2-Cz consistently delivered the highest performance across all tested HTLs, confirming its versatility as an interlayer that is compatible with different types of HTL. The highest power conversion efficiency of 20.9% (0.125 cm2) is achieved when applying the brominated carbazole derivative Br2-Cz on top of the in-house synthesized pyrene-based SAM 4PAPyr. These findings highlight the potential of targeted molecular engineering of interlayers to optimize solar cell performance.
