Solar RRL最新文献

Tin-lead (Sn-Pb) perovskites with narrow bandgaps can be used as bottom cells for tandem cells to boost the efficiency of perovskite solar cells (PSCs). However, the uncontrollable crystallization of Sn–Pb perovskites and the straightforward oxidation of Sn²⁺ to Sn⁴⁺ are two key factors that restrict their efficiency and stability. Compared to the anti-solvent method, vacuum flash assisted solution processing (VASP) offers the advantages of environmental protection and excellent controllability. In this study, we combined VASP with the post-processing of sodium triacetoxyboro-hydride (STAB) as a reducing agent and passivator. The experimental and theoretical results demonstrat that interactions occurred between specific functional groups (−CH₃, B–H, and CO) and the perovskite. Therefore, the Sn²⁺ oxidation was successfully inhibited and the film quality was improved. The efficiency of the optimized PSCs with the STAB increased from 18.2% to 21.64%, which is the highest power conversion efficiency among the Sn–Pb PSCs fabricated using the VASP method. In addition, the device retained 81% of its initial efficiency after being stored in N₂ under −0.1 MPa for 1400 h.

Front side recombination in tunnel oxide passivated contact solar cells is frequently described by the recombination parameters j_0e for the passivated and j_0e,met for the metallized front region. The combination of Al-free metallization pastes and current-assisted contact formation has shown significant reduction of j_0e,met. Such new metallization approaches enable shallower doping profiles and higher sheet resistances R_sheet, which in turn also reduce j_0e. In this study, we provide insight into how to reduce the overall front side recombination, by tailoring the boron dopant profile from atmospheric pressure BBr₃ diffusion processes. The limitation of the dopant dose in the profile leads to a higher R_sheet of the resulting profile. The newly developed homogeneous boron emitter features j_0e = 14 fA cm⁻² at a R_sheet = 161 Ω sq⁻¹, a 62% decrease from the initial value, and an even lower j_0e = 8 fA cm⁻² is determined for an emitter with 330 Ω sq⁻¹. An increased contact resistivity on the front side still poses a challenge for Ag front side pastes despite the use of current-assisted contact formation. Application of an alternative AgAl paste in industrial-type fabricated TOPCon solar cells results in a maximum conversion efficiency of 24.5%.

Designing innovative photocatalysts for nitrogen photofixation is becoming crucial for the development of carbon-neutral ammonia production. Metal halide perovskites (MHPs) provide a rich library of materials with an easy tuning of the semiconductor bandgap in order to integrate them in devices with different functionalities. An under-explored path is their exploitation to run a wide range of photoredox reactions mediated by solar light. Herein, heterojunction is developed based on the vacancy-ordered double-perovskite Cs₂SnBr₆ and carbon nitride nanosheets and demonstrate its ability in running the nitrogen photofixation reaction to produce ammonia under solar light. An investigation is done on full Cs₂SnBr₆/g-C₃N₄ system and an optimal range providing an outstanding ammonia evolution rate up to 270 μmol g⁻¹ h⁻¹is identified, which is quantified by means of ion selective electrode. Mechanistic insight into the photofixation reaction is obtained through a combination of advanced spectroscopy and computational modeling. Efficient ammonia production stems from an effective charge transfer from the perovskite to the nitrogen vacancies on the carbon nitride enabled by the proposed absence of self-trapped excitons in Cs₂SnBr₆, which also provides additional reactive sites through bromide vacancies. This work paves the way to MHP-based catalyst design strategy for sustainable ammonia production.

This study introduces a solvent-free close-spaced sublimation (CSS) method for both perovskite conversion and post-treatment. A PbI₂ layer is deposited via thermal evaporation and subsequently converted into MAPbI₃ using CSS of Methylammonium iodide powder. The resulting MAPbI₃ layer is further passivated with MACl powder using the identical CSS method. Through this post-treatment, it is possible to improve the quality of the perovskite layer, leading to a decrease of defect density and enhancing photovoltaic performances. As a result, device efficiency improves from 14.6% to 16.4%, with notable increases in J _sc and V _oc, along with a reduction in hysteresis. The potential of this solvent-free CSS method is demonstrated, making it a promising approach for large-scale manufacturing of perovskite and tandem solar cells.

Promoting infrared (IR) response is crucial to boost the short-circuit current density (J_SC) of thinner silicon heterojunction (SHJ) solar cells. Herein, tantalum-doped tin oxide (TaTO) film is not only a transparent conductive film but also used as rear reflector stacked with multiple-doped indium oxide (IMO) to promote the IR quantum efficiency of SHJ solar cells. Stack films (IMO/TaTO) are prepared and their structural and optical–electrical properties were studied. IMO/TaTO stack film is a layer of polycrystalline IMO film covered by amorphous TaTO film. Given the low surface roughness of amorphous film, the IMO/TaTO stack films show higher reflectance than single-IMO film in IR region. The carrier concentration of IMO/TaTO stack film is 1.06 × 10²⁰ cm⁻³, one third of IMO films, leading to low absorption loss in IR region. Therefore, a J_SC gain of 1.55%_rel for industrial SHJ solar cells with rear IMO/TaTO films is acquired due to improvement of IR response. Finally, an average power conversion efficiency gain of 0.27%_abs is come through, providing that stacks with less indium content in the rear side of SHJ solar cells is feasible to enhance the efficiency of SHJ solar cells.

The morphology of active layer of the organic solar cells (OSCs) tends to transition toward its lowest energy conformation under thermal stress, significantly limiting the stability of OSCs. In this study, ethyl cellulose (EC) is utilized as an additive in the active layer of the typical PM6:Y6 and other systems. Due to the strong interaction between the hydroxyl groups of EC and the heteroatoms in the organic semiconductors, their bulk heterojunction nanomorphology is locked, thereby enhancing device thermal stability. Under thermal stress at 65 °C for 1,000 h, the PM6:Y6 device incorporating EC demonstrates excellent stability nearly without performance loss. Furthermore, compared to the control device, the device exhibits improved thermal stability under a range of more stringent aging conditions. Additionally, the EC additive shows broad applicability in various active layer systems, effectively enhancing their thermal stability. This work offers a promising approach for developing stable nanomorphology structures in OSCs.

Throughout the development of silicon heterojunction (SHJ) solar cells, the transparent conductive oxide has been regarded as an essential component of their front electrode, facilitating lateral charge transport of photogenerated carriers toward the front metal grid fingers. In rear junction (RJ)-SHJ solar cells, the (n)c-Si bulk is known to support the lateral electron transport at maximum power point injection level, provided that the contact resistance of the front contact stack is sufficiently low. This enables experimental RJ-SHJ solar cell architectures featuring a localized front carrier-selective passivating contact exclusively covering the area contacted by the metal grid. Herein, a top-down approach to the synthesis of this type of architecture is studied and its optical and electrical performance applied to different (n)-type contacts are investigated. Additionally, the potential of the localized contact architecture through Cu-plated RJ-SHJ solar cells is demonstrated. These solar cell demonstrators feature high short-circuit current density of 40.5 mA cm⁻², without significantly compromising their open-circuit voltage or fill factor, enabling efficiencies well above 23%, a 2%_abs improvement compared to their state before localization of the front contact.

The influence of minimal amounts of Ag (0.5–1.4 at%) on elemental distribution and crystalline quality of (Ag,Cu)(In,Ga)Se₂ (ACIGSe) absorbers grown by the three-stage coevaporation without added alkali elements is reported. The elemental ratios affect the amount of Ag to be uniformly incorporated into the chalcopyrite absorber and the open-circuit voltage (V_OC) of the ACIGSe solar cell devices. Ag-containing absorbers deposited at 530 °C achieve a best photoconversion efficiency of 18.2%. Due to an increased V_OC, ACIGSe absorbers perform better than their Ag-free variants at low deposition temperatures. The factors contributing to this increased V_OC of low-temperature devices are: 1) enhanced elemental Ga and In interdiffusion and hence their spatial distribution across the absorber thickness, leading to an increase in the minimum bandgap, 2) an improved absorber crystalline quality with larger grains resulting in high quasi-Fermi-level splitting and lower nonradiative losses. The photoluminescence data obtained on the ACIGSe absorbers reveal the corresponding variations in their bandgap and photoluminescence quantum yield. These material-level insights into Ag incorporation in chalcopyrite help to advance the development of chalcopyrite-based tandem solar cells, which—so far—is limited by the requirement of high deposition temperatures.

Photothermocatalytic dry reforming of methane (DRM) can convert CH₄ and CO₂ into syngas, offering an effective approach to reducing greenhouse gas emissions. However, photothermocatalytic DRM reaction generally needs a high light intensity surpassing 192 kW m⁻² to attain high light-fuel conversion. Also, catalysts applied to photothermocatalytic DRM are liable to inactivation due to carbon deposition. Herein, a nanocomposite of Ni nanoparticles supported on Ni- and Y-doped Al₂O₃ (Ni/Ni-Y₂-Al₂O₃) is prepared. It achieves high H₂ and CO production rates with a light-to-fuel efficiency (29.2%) at a lower intensity (80.1 kW m⁻²). Meanwhile, it sustains excellent photothermocatalytic durability and accomplishes a 37-fold reduction in carbon deposition rate compared to Ni/Al₂O₃. The substantially enhanced catalytic activity and carbon resistance of Ni/Ni-Y₂-Al₂O₃ are correlated with accelerating carbon species (C*) oxidation (the rate-determining steps of DRM). This acceleration derives from the synergetic effect and carbonate species resulting from Y doping, which participate in C* oxidation via two separate reaction pathways. When in light, the synergetic effect further facilitates C* oxidation. Simultaneously, light immensely reduces activation energy, activates the NiO bonds at the interface region, and expedites the reaction between carbonate species and C* in the interface, enhancing catalytic activity and carbon resistance.

The rapid growth of the Internet of Things ecosystem has increased the need for sustainable, cost-effective energy sources for indoor low-power devices. Indoor photovoltaics offer a solution by harnessing ambient indoor lighting, with dye-sensitized solar cells (DSSCs) emerging as strong candidates for these applications. When it comes to indoor environments, there is an increased demand for nontoxic and nonflammable solvents for electrolytes. The use of water-based electrolytes is a promising way to address these issues, while ensuring the eco-friendliness and sustainability of these devices. Herein, a DSSC system is employed featuring an aqueous gel electrolyte composed of xanthan gum, a biosourced polymer, and an iodide/triiodide redox couple. The performances of the cells are characterized under LED lighting, reaching efficiencies up to 3.5% in indoor conditions, and then integrated with an electric double-layer capacitor, also based on a xanthan gum gel electrolyte, resulting in a fully aqueous device for indoor light-energy harvesting and storage with an overall photoelectric conversion and storage efficiency of 1.45%.