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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

On-demand formation of Lewis bases for efficient and stable perovskite solar cells

In the fabrication of FAPbI 3 -based perovskite solar cells, Lewis bases play a crucial role in facilitating the formation of the desired photovoltaic α-phase. However, an inherent contradiction exists in their role: they must strongly bind to stabilize the intermediate δ-phase, yet weakly bind for rapid removal to enable phase transition and grain growth. To resolve this conflict, we introduced an on-demand Lewis base molecule formation strategy. This approach utilized Lewis-acid-containing organic salts as synthesis additives, which deprotonated to generate Lewis bases precisely when needed and could be reprotonated back to salts for rapid removal once their role is fulfilled. This method promoted the optimal crystallization of α-phase FAPbI 3 perovskite films, ensuring the uniform vertical distribution of A-site cations, larger grain sizes and fewer voids at buried interfaces. Perovskite solar cells incorporating semicarbazide hydrochloride achieved an efficiency of 26.1%, with a National Renewable Energy Laboratory-certified quasi-steady-state efficiency of 25.33%. These cells retained 96% of their initial efficiency after 1,000 h of operation at 85 °C under maximum power point tracking. Additionally, mini-modules with an aperture area of 11.52 cm 2 reached an efficiency of 21.47%. This strategy is broadly applicable to all Lewis-acid-containing organic salts with low acid dissociation constants and offers a universal approach to enhance the performance of perovskite solar cells and modules.

14 SOLAR ENERGY↗
DOE OSTI2025

Optimizing 2D passivation for enhancing performance of fully air-processed carbon electrode-based perovskite solar cells

Air-processed carbon-based perovskite solar cells (C-PSCs) offer scalable and cost-effective photovoltaic manufacturing but face efficiency loss compared to metal-contact perovskite solar cells. Surface passivation of three-dimensional (3D) perovskites with two-dimensional (2D) perovskite layers has emerged as a promising strategy to enhance device performance. However, the mechanisms by which 2D perovskites more effectively improve C-PSC efficiency and stability remain underexplored. This study investigates the efficacy of 2D/3D heterostructures using n-hexylammonium bromide (C6Br), phenethylammonium iodide (PEAI), and n-octylammonium iodide (OAI) as surface passivators for C-PSCs. C-PSCs treated with C 6 Br achieved a champion power conversion efficiency (PCE) of 21.0%. This enhancement is attributed to superior defect passivation, improved charge extraction, and suppressed non-radiative recombination. Transient ion-drift characterization demonstrates that C 6 Br and OAI reduce ionic conductivity by 2–3 orders of magnitude, correlating with enhanced operational stability under continuous illumination. Our findings highlight the role of short-chain bromide cations (C 6 Br) in optimizing halide-mediated defect healing and interfacial band alignment, positioning 2D-passivated C-PSCs as viable competitors to conventional metal-contact perovskite solar cells.

14 SOLAR ENERGY↗
DOE OSTI2026

Ultrafast (1‐5 sec) Lamination of Perovskite Solar Cells With Self‐Encapsulation Using Rapid Joule Heating

Perovskite solar cells (PSCs) are traditionally fabricated using sequential layer‐by‐layer deposition, in which each layer of the device is processed on top of the preceding layer. This constrains the processing techniques and selection of transport layer materials that can be used in the solar cell. To overcome these challenges, two half‐cells can be processed independently and then diffusion‐bonded through a lamination process. However, current lamination processes for perovskite solar cells suffer from relatively long process times, which can limit throughput when moving toward high‐volume manufacturing. In this study, a custom platform was designed for rapid‐joule heating of perovskite materials and devices. This enabled more than a 99% reduction in lamination time from 26 min to 1 s. Perovskite samples that were laminated in 1 s exhibited comparable values of percent bonded area, interfacial toughness, grain domain size, and X‐ray diffraction spectra to those laminated in greater than 10 min. As a proof‐of‐concept, 18.3% efficient devices were successfully laminated in 5 s. A transient heat transfer model was developed to describe the relationship between the perovskite temperature and the electrical power supplied to the heaters, establishing a baseline for predicting processing conditions in large‐scale manufacturing systems. Ultra‐fast lamination provides a pathway toward scalable roll‐to‐roll or sheet‐to‐sheet manufacturing of PSCs.

heat transfer↗
DOE OSTI2026

Impact of the Annealing Temperature on the Local Se Distribution and Optical Properties in CdSexTe1-x Solar Cells by Multimodal X-ray Microscopy

The introduction of Se in CdTe solar-cell absorbers has led to multiple beneficial effects in the devices, including an increased short-circuit current and an extended charge-carrier lifetime. A critical manufacturing step of CdSexTe1-x solar cells is CdCl2 annealing at high temperatures, during which Se diffuses through the absorber layer. Understanding the local Se distribution in the absorber and its impact on optical properties of the material is key for the further development of this thin-film solar cell technology. In a multimodal x-ray scanning microscopy approach, we investigated the impact of the annealing temperature of CdSexTe1-x solar cells on the Se distribution and on optical characteristics of the material. For this purpose, we exploited an upgraded x-ray excited optical luminescence (XEOL) detection unit that enables simultaneous spectrally and temporally resolved XEOL mapping at synchrotron facilities that are ideal for studying thin-film solar-cell materials with hard x-rays featuring high penetration depth and lateral resolution.

14 SOLAR ENERGY↗
DOE OSTI2025

Ionic liquids improve the long-term stability of perovskite solar cells

Achieving operational stability in halide perovskite solar cells remains a critical challenge for commercialization. Ionic liquids are promising bulk modifiers, yet their mechanistic role in perovskite crystallization is poorly understood. Here we engineered an ionic liquid, methoxyethoxymethyl-1-methylimidazole chloride (MEM-MIM-Cl), with an ethylene glycol ether side chain that regulates perovskite growth and stabilizes buried interfaces via synergistic interactions with NiO x . MEM-MIM-Cl induces a novel intermediate phase through chelation with undercoordinated Pb(II), suppressing defects and defect-induced degradation. Solar cells incorporating MEM-MIM-Cl achieved a power conversion efficiency of 25.9% and retained 90% of their initial performance after 1,500 h under continuous 1-sun illumination and 90 °C thermal stress—surpassing prior benchmarks under milder ageing conditions. Furthermore, diurnal cyclic ageing revealed unprecedented fatigue resistance, highlighting the dual role of MEM-MIM-Cl in simultaneously enhancing efficiency and operational resilience. In conclusion, this work elucidates design principles for functional ionic liquids while advancing perovskite photovoltaics towards industrial viability.

14 SOLAR ENERGY↗
DOE OSTI2024

Unraveling the Combined Photothermal Stability of Common Perovskite Solar Cell Compositions

In halide perovskite solar cells, certain compositions, especially those with a high mixture of anions, degrade rapidly. Here, in this study, a degradation study compares the photo (exposure to light), thermal (exposure to elevated temperatures), and photo-plus-thermal (combination) stability of three representative perovskite compositions chosen for their relatively high performance and to independently test anion versus cation effects. Based upon experience and reports, the compositions studied are triple cation with a high Br ratio (Cs 0.05 (FA 0.98 MA 0.02 ) 0.95 Pb(I 0.5 Br 0.5 ) 3 ), all iodide with a moderately high Cs ratio (FA 0.8 Cs 0.2 PbI 3 ), and FA-dominated triple cation (Cs 0.05 (FA 0.98 MA 0.02 ) 0.95 Pb(I 0.98 Br 0.02 ) 3 ). Cs 0.05 (FA 0.98 MA 0.02 ) 0.95 Pb(I 0.98 Br 0.02 ) 3 displayed the best combined photo-plus-thermal stability. Degradation mechanisms were investigated by comparing the morphology, surface composition, and bulk and interface carrier dynamics. Under the harshest aging conditions (photo-plus-thermal), phase segregation and vaporization of organic cations occurred, along with the appearance of high-energy states indicating the interaction with C 60 . The findings were verified on perovskite films blade-coated in air used in devices (FTO/NiOx/SAM/Perovskite/C 60 /BCP/Cu), achieving an efficiency of 21.9% alongside correlated stability.

14 SOLAR ENERGY↗
DOE OSTI2025

Cold air quench control of local crystallization environment in fully air-processed carbon-based perovskite solar cells

Carbon-based perovskite solar cells (C-PSCs) present a low-cost route to efficient photovoltaic technology. Gas quenching is an essential process commonly used for solvent extraction in scalable module fabrication using solution processes, but film quality remains highly sensitive to the localized environmental processing temperature, especially during intermediate phase transitions before perovskite film high temperature annealing. In this study, we introduce a cold air quench strategy to precisely control the local crystallization temperature that simultaneously promotes uniform crystallization and facilitates strain relaxation in fully air-processed C-PSCs. It is found that implementing dry air at 10 °C as the quenching gas yields a champion power conversion efficiency (PCE) of 20.52 %, with preferential (110) orientation and reduced, homogenized in-plane strain. This newly developed technique of a cost-effective low temperature air quenching process also enhances carrier lifetime, reduces interface recombination, and improves charge extraction. Furthermore, this work presents cold air quenching as a scalable, economic method to control perovskite crystallization and strain in C-PSC fabrication, advancing the industrial viability of high-performance perovskite modules.

14 SOLAR ENERGY↗
DOE OSTI2025

Imaging Power Losses in CdSeTe Solar Cells

Much of the research on CdSeTe photovoltaics is focused on improving the open-circuit voltage (V oc ) of the solar cell. But solar cells operate at the maximum power point (MPP) rather than at V oc . The recombination processes at MPP may be different than those at V oc , and increasing the power output at MPP is the key to advancing efficiency. Here, we introduce a camera-based PL imaging system that enables power loss analysis under operating conditions and across cm-sized areas covering multiple cells. The instrument is demonstrated with CdSeTe devices having efficiencies greater than 19%. An implied current density versus implied voltage (iJV) curve can be produced at each pixel with <20 µm resolution. We find that regions with high implied open circuit voltage are often those with low implied fill factor, showing that voltage loss analysis at open circuit is not sufficient to understand power losses under operating conditions. Measurement of JV curves as a function of irradiance can also be performed in the system, which allows series resistance-free pseudo JV (pJV) curves to be produced. Comparison of pJV to measured JV and iJV curves allows further analysis of the operational losses, pointing the way to higher efficiency.

14 SOLAR ENERGY↗
DOE OSTI2025

Low-Cost, Screen-Printed Silver Metal Complex Inks for Silicon Heterojunction Solar Cells

Screen printing using metal particle pastes, the current photovoltaic industry metallization standard, provides fast and reliable metal grids for silicon solar cells. Recently, metal complex or reactive metal inks are attracting research interest due to their significantly low cost and higher performance compared to traditional nanoparticle silver pastes. In this work, we demonstrate, for the first time, screen-printed high-efficiency silicon heterojunction solar cells metallized by silver metal complex inks on industrial G1-size (158.75 x 158.75 mm2) wafers. We demonstrate screen-printed Ag metal complex ink grid patterns with continuous fingers ~100-120 ..mu..m wide. The printed Ag grid is very thin (~1 ..mu..m), which is an order of magnitude thinner than the current ~20-30 ..mu..m fingers printed with low-temperature nanoparticle-based pastes. Double printing allows silicon heterojunction devices with efficiencies >20%. This is the highest efficiency so far, to our knowledge, of industrial solar cell precursors using this metallization technology. Simulation results suggested that increasing the thickness of the metal film does not significantly improve efficiency due to the dense, highly conductive films. So, a single print of ~1 ..mu..m finger would be enough to produce cells that perform similarly to a ~20 ..mu..m thick nanoparticle paste printed cells. Additionally, solar cells printed on G1 wafers with silver metal complex ink required more than 10 times less silver (~0.03 g) compared to those using silver/copper nanoparticle paste (~0.4 g of Ag). These results indicate that metal complex inks are a very promising replacement for silver nanoparticle pastes for industrial-scale metallization in an age of resource scarcity and high costs of noble metals.

14 SOLAR ENERGY↗
DOE OSTI2025

Wafer-Free Crystalline Silicon Solar Cells (CRADA Final Report)

This CRADA project, based on the DOE Solar Energy Technologies Office (SETO) Solar Prize Voucher program, helped Leap Photovoltaics to develop methodologies to immobilize Si particles by permanently attaching them to an Al-coated substrate and thereby forming carrier-selective electrical contacts to the Si particles. The bigger goal was to help Leap Photovoltaics develop these immobilized and contacted particle arrays into relatively efficient, inexpensive, and industrially relevant solar cells. By using Si particles instead of wafers in a solar cell absorber layer, one can avoid costs associated with growing monocrystalline Si ingots, then diamond-sawing them into wafers, then processing wafers into cells – a mainstream practice in today's high-efficiency Si cell and module technology. Monocrystalline or polycrystalline Si particles can be obtained in various ways: for example, Si kerf from wafer sawing is monocrystalline; recycled Si cell wafers can be ball-milled into particles; particles can be grown using various gas-phase techniques (mostly from SiH4). These Si particles can be assembled onto a substrate and serve as an absorber layer for the solar cell, absorbing photons to generate photocarriers. The challenge with this technique is to collect photocarriers from individual Si particles, with separation of photogenerated electrons to the negative cell’s electrode and positive photogenerated holes to the positive electrode. Therefore, each particle must have two isolated, carrier-selective contacts: one for electrons and one for holes. Plus, particles need to be immobilized onto a solid substrate. The goal of this work was focused on the immobilization of Si particles and creating hole-selective contact to them at the same time, using industrially relevant Si photovoltaic (PV) cell technology: screen printing of Al back-surface field electrodes. This is used in the mainstream Propane Education and Research Council (PERC) technology for hole-collecting contacts at the back of the cell. The work performed at NREL consisted of screen printing of Al metal paste on substrates, spreading Si particles onto it, and thermally processing the structures to form hole-collecting contacts. The final structures were investigated by scanning electron microscopy (SEM) after focused ion beam (FIB) cross-sectioning and polishing. The work was done jointly by NREL staff and Leap Photovoltaics (Leap PV) employees stationed at NREL. The samples were then taken to Leap PV for further processing. Training the Leap PV employee on various NREL techniques (laser cutting, screen printing, thermal processing, characterization) was part of the scope.

14 SOLAR ENERGY↗
DOE OSTI2025

Characterization of dangling bond defects at the crystalline Si/SiO x interface in a polycrystalline Si passivating contact solar cell at room temperature with electrically detected magnetic resonance spectroscopy

Monocrystalline silicon solar cells can achieve photoconversion efficiencies exceeding 26%; however, performance-limiting defects that trap carriers continue to be a challenge. In this work, we have characterized Si solar cells with tunneling SiO x /polycrystalline-Si (poly-Si) passivating contacts (TOPCon) on As-doped Czochralski Si wafers with electrically detected magnetic resonance (EDMR) spectroscopy. We fabricated 2 × 20 mm 2 TOPCon-like mini solar cells with edge passivation alongside larger 4 cm 2 sister cells and obtained similar device characteristics. We performed EDMR spectroscopy at 300 K on two minicells with different degrees of surface passivation based on the recombination parameter, J o , values of 40 and 310 fA/cm2. We optimized the resolution and the signal-to-noise ratio of the EDMR response of the minicells by varying the forward bias voltage and the magnetic field modulation amplitude. We detect two distinct signals with EDMR spectroscopy, an axial-like signal at g = 2.009, 2.0087, and 2.0015, and an isotropic signal at g = 2.0024, which we attribute to Si dangling bonds (P b0 and P b centers) and boron–oxygen related defects, respectively, at or near the c-Si/SiO x interface. The EDMR signals were lower for the cell with a lower value of J o , while the ratio of the two defect populations was very similar. The EDMR signal increases with forward bias but drops to zero at bias voltages >0.5 V, consistent with interface defects within or near the boron-doped emitter depletion region. Our study demonstrates a method to fabricate minicells that can be characterized with EDMR spectroscopy to detect industrially relevant defects in TOPCon cells.

14 SOLAR ENERGY↗
DOE OSTI2024

Effect of ZnO and PEDOT:PSS charge selective layers on photovoltage of cuprous oxide (Cu 2 O) heterojunction solar cells

Electrochemical deposition (ECD) of Cu 2 O provides a scalable and low temperature pathway to solar cells with a theoretical high energy conversion efficiency of 23%, based on the 2.0–2.2 eV band gap of Cu 2 O. However, existing ECD-Cu 2 O devices are plagued by poor crystallinity and low selectivity of the electron and hole transport layers. Here we use Vibrating Kelvin Probe Surface Photovoltage Spectroscopy (VKP-SPV) to probe the charge transfer selectivity in FTO/ZnO/Cu 2 O/PEDOT:PSS/Ni heterojunction solar cells. Selective electron extraction is achieved at the ZnO back contact to Cu 2 O, as confirmed by a negative surface photovoltage signal. While the uncoated Cu 2 O surface is electron-selective due to the formation of a hole depletion layer, spin coating of a PEDOT:PSS film turns it into a hole-selective interface. After adding nickel metal ink top electrodes, functional 1.0 cm 2 solar cells with power conversion efficiency (PCE) of up to 0.07%, 195 mV open-circuit voltage, and 1.28 mA cm –2 short-circuit photocurrent are achieved. The photovoltaic performance is higher for aluminum doped zinc oxide (AZO) substrates than for fluorine doped tin oxide (FTO) due to the presence of a n-/p-junction that further increases the electron selectivity of the AZO/ZnO/Cu 2 O contacts. Overall, this work demonstrates the first application of PEDOT:PSS as a hole transport layer (HTL) for Cu 2 O and the use of VKP-SPV to measure the photovoltage contributions of the Cu 2 O interfaces. Furthermore, the ability to fabricate Cu 2 O solar cells at near room temperature without the use of vacuum methods or rare elements is an important step towards a scalable Cu 2 O PV technology.

14 SOLAR ENERGY↗
DOE OSTI2026

Semi-Transparent Perovskite Solar Cells in a Stacked Tandem Module: Cooperative Research and Development Final Report, CRADA Number CRD-19-00810

This project seeks to develop device design, materials composition, and processing tools and parameters to fabricate semi-transparent perovskite solar cells and modules for application in stand-alone products or added to other solar cells in a mechanically stacked tandem configuration. This technology presents significant advanced manufacturing challenges and opportunities in getting to scale, including development of perovskite inks, scalable perovskite and heterojunction deposition and annealing processes, heterojunction composition, transparent electrode composition and deposition process, anti-reflection layer composition and deposition process, and cell to module integration processes. Modification 5: The proposed project seeks to develop device design, materials composition, and processing tools and parameters to fabricate semi-transparent perovskite solar cells and modules for application in stand-alone products or added to other solar cells in a mechanically-stacked tandem configuration. This technology presents significant advanced manufacturing challenges and opportunities in getting to scale, including development of perovskite inks, scalable perovskite and heterojunction deposition and annealing processes, heterojunction composition, transparent electrode composition and deposition process, passivation layers including in module scribes, anti-reflection layer composition and deposition process, and cell to module integration processes. Advanced metrology and characterization will be performed on perovskite films, cells and module. Furthermore, we will examine module or materials recycling for circular economy considerations. Modifcation 6: Gigahertz frequency microwave pump-probe spectroscopies are highly sensitive to thin film semiconductor photoconductivity of individual and stacks of layers that comprise perovskite solar cells. As such, these techniques will be used to qualify reproducibility and quality correlations during the manufacturing process. Modification 7: Mechanical adhesion of top contacts within perovskite modules significantly impacts the durability of the module when exposed to accelerated degradation testing. The adhesion between the perovskite/transport layer interface and the transport layer/top contact interface are both very sensitive small changes in processing. ALD processing conditions of the transport layer will be tuned to optimize the mechanical adhesion within the perovskite module stack.

14 SOLAR ENERGY↗
DOE OSTI2024

In situ energetics modulation enables high-efficiency and stable inverted perovskite solar cells

In contrast to conventional (n-i-p) perovskite solar cells (PSCs), inverted (p-i-n) PSCs offer enhanced stability and integrability with tandem solar cell architectures, which have garnered increasing interest. However, p-i-n cells suffer from energy level misalignment with transport layers, imbalanced transport of photo-generated electrons and holes, and significant defects with the perovskite films. Here we introduce tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB), a nonionic n-type molecule that, through hydrogen bonding and Lewis acid-base reactions with perovskite surfaces or grain boundaries, enables in situ modulation of perovskite energetics, effectively mitigating the key challenges of p-i-n PSCs. The p-i-n PSCs incorporating 3TPYMB achieve a certified quasi-steady-state power conversion efficiency of 24.55 +- 0.33%, with a reverse scan efficiency of 25.58%. Finally, they also exhibit exceptional stability, with unencapsulated devices retaining 97.8% of their initial efficiency after 1,800 h of continuous operation at maximum power point under N 2 atmosphere, 1 sun illumination and 60 °C conditions.

14 SOLAR ENERGY↗
DOE OSTI2025

Increased Voltage in CdSe Solar Cells by Mitigation of Charge Carrier Trapping Due to Se Vacancies

Cadmium selenide (CdSe), with a 1.7 eV bandgap, is a promising high-bandgap semiconductor for tandem solar cells, yet device efficiencies are hindered by rapid minority carrier recombination. Here, in this study, polycrystalline CdSe solar cells are investigated using radiative emission spectroscopy, time-resolved photoluminescence, and density functional theory, revealing fast (sub-nanosecond) minority carrier trapping by selenium vacancy-related defect states with densities of (5–50) × 10 17 cm −3 , limiting carrier mobility and increasing recombination. By reducing absorber thickness to ≈0.5 µm, trapping effects are mitigated, achieving a record open-circuit voltage of 917 mV, a 165 mV improvement over prior reports. These findings clarify the role of Se vacancies in limiting CdSe solar cell performance and provide insights applicable to CdSe and CdSeTe thin-film photovoltaics. This work advances understanding of defect-mediated losses in II–VI semiconductors and suggests pathways for improving solar cell performance through defect control.

14 SOLAR ENERGY↗
DOE OSTI2026

An Open Source Perovskite Solar Cell Curve Tracer

When developing systems for perovskite solar cells (PSCs), it is important to have a testing platform that closely resembles your deployed systems. While developing a 1 U CubeSat, the Big Red Sat-1 at the University of Nebraska-Lincoln, we found a lack of passive curve tracing instrumentation, which we needed for our mission. To that end, we developed a benchtop passive curve tracer that leverages the Ossila Solar Simulator as an AM1.5 light source. This device utilizes a ladder of switched resistors and a precision voltage and current measurement to achieve the curve tracing. It also integrates a common-anode multiplexer to switch through multipixel PSCs. Finally, the solar cell holder is separate from the main measurement system, so various substrates sizes and pixel counts can be supported. This system is tested using various PSCs. It has been open sourced to enable reuse in future systems that may benefit from the lower power consumption and flight heritage.

14 SOLAR ENERGY↗
DOE OSTI2025

Toward Fullerene-Free PIN Perovskite Solar Cells

We highlight opportunities for a transformative shift in perovskite solar cell design by expanding electron transport layers (ETLs) beyond fullerenes. Fullerenes have known limitations, including constraints on open-circuit voltage, stability, and mechanical integrity. Recently, fullerene-free p-i-n cells with power conversion efficiencies exceeding 25% have been demonstrated via both naphthalene diimide-SnO x bilayers and nonfullerene acceptor-based ETLs. Despite successes, fullerenes remain the de facto ETLs for perovskites. Drawing lessons from organic photovoltaics, where it took decades to transition from fullerenes to more broadly available and efficient materials, we explore pathways to accelerate the development and adoption of fullerene-free ETLs. This requires understanding the similarities and differences between organic and perovskite solar cells, which will necessitate carefully designing fullerene replacements with both, high efficiency and also, critically, durability under operation. Here, we incorporate literature data to facilitate comparisons, and independently conduct fracture energy measurements for alternative ETL configurations to motivate their adoption.

14 SOLAR ENERGY↗
DOE OSTI2025

Dual aggregation steering in bulk-heterojunction via solvent engineering toward efficient and stable binary organic solar cells

In high-performance organic solar cells (OSCs), efficient charge transport hinges on a well-optimized morphology of the photoactive layer, which depends critically on controlled aggregation and favorable interactions between donor and acceptor materials. In this work, we introduce a cascade solvent system comprising high-boiling-point ethylbenzene (EB) and low-boiling-point chloroform (CF) to finely tune the aggregation behavior of the D18 donor and L8-BO acceptor. The incorporation of EB not only promotes the H-aggregation of D18 and the J-aggregation of L8-BO but also facilitates the formation of ideal nanoscale phase separation, thereby suppressing bimolecular recombination. As a result, devices processed with the EB/CF solvent blend achieve a best power conversion efficiency (PCE) of 19.6 % and enhanced operational stability, outperforming those fabricated with pure CF (17.1 %). In conclusion, this study offers a reliable and effective strategy for optimizing donor and acceptor aggregation, providing a viable pathway toward higher-performance OSCs.

36 MATERIALS SCIENCE↗