Solar RRL最新文献

The rising demand for sustainable low-power devices has driven interest in indoor photovoltaic (IPV) technologies for Internet of Things (IoT) applications. Composed of earth-abundant and non-toxic elements, Kesterite-based Cu₂ZnSnS₄ (CZTS) solar cells are highly attractive for IPV. This study systematically investigates the effects of sodium (Na), lithium (Li), and Na–Li co-doping on solution-processed CZTS devices. A comprehensive analysis reveals that Na-doping substantially improves crystallinity and grain morphology, significantly boosting efficiency, whereas Li alone has minimal impact. Notably, Na–Li co-doping achieves a 10.1% efficiency under AM 1.5G illumination, outperforming both the reference and singly doped devices. The co-doping synergy arises from Na-induced grain growth and Li-induced defect passivation and carrier concentration regulation. These devices exhibit high adaptability under 20 different indoor lighting conditions representative of real-world environments, achieving up to 15.1% power conversion efficiency under 3000 K illumination at 2.93 mW cm⁻²;—the highest reported indoor efficiency for CZTS cells. Their stable open-circuit voltage, high fill factor, and consistent efficiency across various color temperatures and intensities underline their suitability for IPV applications. Future work should focus on improving bandgap alignment with indoor light spectra to further enhance the efficiency of this eco-friendly technology for IoT energy solutions.

To commercialize perovskite solar cells (PSCs), it is crucial to develop cost-effective, dopant-free hole transport layers (HTLs) that can be processed at low temperatures. Herein, a dopant-free small molecular material 4,4′,4′-Tris[2-naphthyl(phenyl)amino]triphenylamine (2TNATA) was utilized in inverted PSCs as a HTL. The position of the highest occupied molecular orbital energy of 2TNATA is properly aligned with the perovskite valence band maximum. Moreover, 2TNATA can be processed at lower temperatures and shows excellent thermal stability. The lead (Pb) perovskite on 2TNATA exhibited superior crystallinity and morphology compared to the perovskite on poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA). Furthermore, the carrier kinetics in 2TNATA-based PSCs was superior to PTAA and PEDOT:PSS-based PSCs. Consequently, an outstanding power conversion efficiency (PCE) of 20.58% was observed from the 2TNATA HTL-based 0.09 cm² PSCs, while PTAA and PEDOT:PSS HTLs-based 0.09 cm² PSCs showed PCE of 19.36% and 14.35%, respectively. Moreover, the 2TNATA HTL-based 1.0 cm² PSCs demonstrated an impressive PCE of 20.04%. The results indicate that 2TNATA might be a promising HTL for the inexpensive and efficient inverted PSCs.

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.