Chen Weijie

A novel 2D-conjugated BDT-based polymer PBDB-tvt is designed and synthesized. Acting as a multifunctional interlayer, it enhances light absorption, optimizes phase distribution, and charge behavior, enabling SD-hybrid devices to reach a PCE of 20.3% with good stability. This work highlights the importance of rational molecular design for advancing high-efficiency OSCs.

Abstract

The bicontinuous active layer morphology plays a crucial role in affecting the charge transport/recombination in organic solar cells (OSCs). However, the conventional bulk heterojunction (BHJ) blending typically results in an uncontrollable vertical phase distribution, hindering further improvement in power conversion efficiency (PCE). Here, we designed a two-dimensional conjugated polymer donor PBDB-tvt by incorporating a long-conjugated side chain, chlorinated alkylthio-thiophene-vinyl-thiophene (tvt), onto the benzodithiophene (BDT) unit. The extended structure up-shifts energy level, enhances optical absorption, and improves charge transport. Interestingly, PBDB-tvt shows selective solubility in common processing solvents, making it suitable for sequential deposition. By using it as the interlayer between the electrode modification layer and bulk heterojunction, we constructed a hybrid device (functional modification layer/BHJ) configuration. The tailored structure not only brings improved phase distribution but also enhances light utilization in the short-wavelength region, which leads to a simultaneous increase of photovoltaic parameters, including open-circuit voltage, short-circuit current density, and fill factor. As a result, the best device achieves a maximum PCE of 20.3%. This contribution highlights the pivotal role of a multifunctional interlayer in enhancing the light absorption and controlling the active layer morphology, providing a feasible method to further improve the photovoltaic performance of OSCs.

Nature Communications, Published online: 17 October 2025; doi:10.1038/s41467-025-64274-5

Practical implementation of all-perovskite tandem solar cells faces challenges due to the self-reinforcing photothermal-mechanical degradation mechanism. Here, authors employ a polyamine ligand to establish I-Sn-N coordination for stabilizing lattice framework, achieving device efficiency of 29.6%.

Nature Communications, Published online: 28 October 2025; doi:10.1038/s41467-025-64545-1

Achieving long-term phase-stabilized formamidinium (FA)-based perovskites remains challenging. Here, authors integrate ferroelectric CsMnBr3 nanocrystals into FA-based perovskites for ferroelectric field-mediated structural regulation, achieving maximum efficiency of 26.62% for stable solar cells.

Nature Materials, Published online: 22 October 2025; doi:10.1038/s41563-025-02375-8

Stability issues hinder the commercialization of perovskite solar cells. An evaporated, highly oriented wide-bandgap perovskite film is reported, enabled through an intermediate phase evolution, resulting in enhanced stability and efficiency.

Nature Photonics, Published online: 20 October 2025; doi:10.1038/s41566-025-01778-y

An engineered self-assembled monolayer improves perovskite crystallization, enabling perovskite–silicon tandem solar cells with a certified power conversion efficiency of 33.59%, 90% of which is maintained after 2,000 h of operation at ambient temperature.

Nature Photonics, Published online: 21 October 2025; doi:10.1038/s41566-025-01768-0

A layer-by-layer thermal evaporation strategy enables thermally evaporated inverted perovskite solar cells with a power conversion efficiency of 25.19%, maintaining about 95% of their initial efficiency after 1,000 h of operation.

Nature Energy, Published online: 17 October 2025; doi:10.1038/s41560-025-01885-8

Thermal stability remains a key challenge for organic photovoltaics. Qin et al. now propose a strategy that stabilizes multiple components of the devices, enhancing their resilience under damp heat and thermal cycling conditions.

Nature, Published online: 27 October 2025; doi:10.1038/s41586-025-09785-3

A matrix-confined molecular layer for perovskite photovoltaic modules

Nature, Published online: 27 October 2025; doi:10.1038/s41586-025-09773-7

All-perovskite tandem solar cells with dipolar passivation

Nature Communications, Published online: 06 October 2025; doi:10.1038/s41467-025-64467-y

Reducing non-radiative recombination at the perovskite/electron transport layer interface remains a critical challenge for achieving efficient perovskite/TOPCon silicon tandem solar cells. Here, authors employ bilayer passivation using AlOx/PDAI2 treatment, achieving device efficiency of 31.6%.

Nature Materials, Published online: 23 September 2025; doi:10.1038/s41563-025-02367-8

To address the phase instability issue of perovskites, ammonium propionic acid is introduced to enhance the phase stability of both perovskite layers in perovskite/perovskite/silicon triple-junction solar cells, resulting in improved efficiency and reproducibility.

Nature Materials, Published online: 30 September 2025; doi:10.1038/s41563-025-02368-7

The authors develop a molecular dopant to avoid the dimerization of the electron-selective material phenyl-C61-butyric acid methyl ester, resulting in enhanced stability and efficiency in inverted perovskite solar cells.

Nature Energy, Published online: 01 September 2025; doi:10.1038/s41560-025-01856-z

Lithium doping in spiro-OMeTAD negatively affects the long-term performance of perovskite solar cells. Qin and team map the degradation mechanism under repeated voltage cycling and how lithium-free dopants improve stability.

Nature Energy, Published online: 15 September 2025; doi:10.1038/s41560-025-01860-3

The upscaling of kesterite photovoltaics is challenging and results in low performance. Xiang et al. tune the thiourea/metal precursor ratio to improve the morphology of the kesterite film, achieving 10.1% certified power conversion efficiency in 10.48-cm2 modules.

Nature Energy, Published online: 26 September 2025; doi:10.1038/s41560-025-01862-1

Optimizing the crystallization of the active materials in organic solar cells is challenging. Fu et al. use an acenaphthene additive to induce a two-step crystallization of the non-fullerene acceptor, achieving a certified 20.5% power conversion efficiency.

Nature, Published online: 17 September 2025; doi:10.1038/s41586-025-09509-7

Cross-linkable co-SAMs improve hole-selective SAM stability, preventing defects and thermal degredation in perovskite solar cells, enabling 26.92% efficiency with high heat durability, and guiding the design of more efficient and durable solar cells.

This remarkable work combines supercritical CO₂ chemical engineering, two-dimension plasmon photophysical science, and perovskite photovoltaic technology. It introduces novel concepts like broad - spectrum coupled photon absorption, the intermediate - localized - states model, and optoelectrical - bimodal - coupling engineering. It aims to combat optoelectronic dissipation and enhance energy harvesting via a heterodimensional van der Waals optically coupled system.

Abstract

All-inorganic CsPbX₃ (X = I, Br, Cl) perovskites emerged as a crucial material for addressing the stability bottleneck due to their exceptional resistance to both light-thermal stress. However, their performance is limited by adverse optoelectronic dissipation arising from inadequate photon conversion and chaotic carrier energetics. Herein, the mechanism of the unique nonlinear plasmonic effect in van der Waals 2D MoO_3-x is elucidated, which is mediated by electronic intermediate states. It demonstrates that the 2D MoO_3-x serves as a light-capture-antenna in heterodimensional CsPbX₃-MoO_3-x optically coupled system, contributing to the accumulation the optical field energy on the nanoscale and resulting in a remarkable 59% increase in photon convergence. Additionally, facet-oriented carrier channels can be established through heteroepitaxy along matched Mo-O octahedron. This optoelectrical-bimodal-coupling engineering combined with a bifacial light-harvesting configuration yields a bifacial equivalent efficiency of 27.33%, which stands as the supreme performance in all-inorganic perovskite photovoltaics.

A narrow bandgap acceptor, BTA-4F, featuring a 2-methyl-2H-benzotriazole central core, is fabricated to construct the rear sub-cell of tandem organic solar cells (OSCs). By fine-tuning the optical field distribution in the BAT-4F-based tandem OSC, a power conversion efficiency of 21.5% is achieved (certified as 21.2%), respectively, which marks the arrival of 21% era in the field of OSCs.2

Abstract

Tandem organic solar cells (OSCs) offer a promising strategy for enhancing light utilization and reducing energy loss, presenting significant potential in achieving high power conversion efficiency (PCE). Herein, a narrow bandgap acceptor, BTA-4F, featuring a 2-methyl-2H-benzotriazole (BTA) central core, is fabricated, which is designed for the rear sub-cell of tandem OSCs. Systematic characterizations demonstrate that incorporating strong electron donating groups BTA into central core unit can narrow the bandgap and enhance the electroluminescence external quantum efficiency. These improvements lead to increased current density and reduced voltage loss of single junction OSCs under AM 1.5G illumination and real incident light of the rear sub-cell. Inspiringly, BTA-4F-based single-junction and tandem OSCs achieve outstanding PCEs of 19.5% and 21.5% (Certified as 21.2%), respectively, which represents the milestone of 21% PCE in the field of OSCs. This study highlights the synergistic benefits of molecular design and implementation of tandem architecture as an effective strategy for enhancing photovoltaic performance of OSCs.

In p-i-n structure perovskite solar cells, conventional self-assembled monolayers (SAMs) such as [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) exhibit limited buried interfacial adhesion, compromising device stability. A donor-acceptor SAM, 4-(7-(4-(bis(4-methoxyphenyl)amino-2,5-difluorophenyl)benzo[c][1,2,5]thiadiazol-4-yl)benzoic acid (PAFTB), featuring an enhanced dipole moment and tailored functional groups, improves adhesion by 2.8 times, thereby enhancing both stability and efficiency of the devices.

Abstract

Inverted p-i-n structure perovskite solar cells (PSCs) have outperformed traditional n-i-p PSCs in recent years. A key advancement is the use of self-assembled monolayers (SAMs) as hole transport layers. One class of widely used SAMs is carbazole-based phosphonic acids. However, it is found that these SAMs lack strong binding with transparent conducting oxides (TCO) and perovskite. The weak binding strength results in suboptimal interfacial adhesion of the buried interface, which limits the device's stability. Here, interfacial binding is enhanced by increasing the dipole moment that creates a strong interfacial electric field that enhances electrostatic interactions at the TCO/perovskite interface, while incorporating tailored functional groups in SAMs to improve chemical anchoring to TCO and binding to perovskite. Specifically, the donor-acceptor SAM molecule 4-(7-(4-(bis(4-methoxyphenyl)amino)-2,5-difluorophenyl)benzo[c][1,2,5]thiadiazol-4-yl)benzoic acid (PAFTB) is employed, which features an enhanced dipole moment along with electron-donating and electron-withdrawing functional groups to optimize interfacial interactions. Compared to extensively used [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), PAFTB enhances total interfacial adhesion by 2.8 times, thereby improving the thermal stability of the layer. Using this approach, PSCs are demonstrated with a certified quasi-steady-state power conversion efficiency of 24.9% and maintain 80% of the initial efficiency after 900 h of maximum power point tracking at 85 °C.

The reducing molecules enhance coverage density of self-assembled molecules (SAM) by forming strong coupling with both NiO_x and SAMs, thereby improving interfacial carrier extraction and suppressing interfacial non-radiative recombination. Hence, the as-proposed device obtains a power conversion efficiency (PCE) of 26.34% and impressive operational stability (97.5% initial PCE retention rate for 1000 h).

Abstract

Self-assembled molecules (SAMs) deposited on nickel oxide (NiO_x) are the basis for achieving high-performance inverted perovskite solar cells (PSCs). Unfortunately, the dissolution and redeposition of SAMs caused by the perovskite precursors leads to leaky monolayers, resulting in perovskite degradation and reduced stability. Here, a novel method is reported to realize strong coupling between NiO_x and SAMs via inserted reductant [9tris(2-carboxyethyl)phosphine hydrochloride (TCEP)] for an integrated NiO_x-SAMs hole transport layer (HTL). TCEP reduces NiO_x and in situ forms C═O···Ni coordinated bond and O─H···O─Ni hydrogen bond, while its -COOH is connected with SAM's -PO(OH)₂ by phosphonate and hydrogen bond, which improve the compactness of SAMs, thereby strengthening hole extraction and lowering interfacial non-radiative recombination. Simulation calculations demonstrate that the HTL strongly coupled by TCEP has a stronger adsorption energy, significantly improving device long-term stability. Therefore, the device based on integrated NiO_x-SAMs HTL obtains a substantial efficiency of 26.34%. The devices maintain an impressive 97.5% of their original efficiency after 1000 h of operation under 1-sun illumination and 90.1% after 1000 h of thermal treatment at 85 °C in nitrogen atmosphere. This work offers new horizons for designing NiO_x-based HTLs with high SAMs coverage for high-performance PSCs.

An additive (NH₄SCN) ligands-assisted perovskite crystallization dynamics regulation strategy is investigated in this work. Which is proved to modulate both the nucleation and crystal growth progresses synchronously in virtue of the interaction affinity between NH₄ ⁺/ SCN^- ligands and the Pb─I framework or FA⁺. Ultimately, perovskite films with superior optoelectronic characteristics are achieved accompanied by a satisfactory performance of relevant PSCs.

Abstract

Despite the dazzling progress since the emergence of perovskite solar cells (PSCs), a significant ideal-reality discrepancy with respect to the open-circuit voltage (V _OC) still reminds the primarily weak parameter, inducing the limited power conversion efficiency (PCE) relative to its Shockley-Queisser theoretical limit. Eliminating the detrimental non-radiative recombination centers enriched at the surface/grain boundaries of perovskite films is generally regarded as the key approaches to bridge this gap. Herein, a perovskite crystallization dynamic regulation template is conducted to ensure the realization of both rapid nucleation and suppressed crystal growth through the synchronous incorporation of SCN⁻ and volatility NH₄ ⁺ ligands. Thereby promoting the formation of high-quality perovskite films with enlarged grain size, superior crystallinity, ordered surface texture and compensated residual strain. Notably, residual SCN⁻ ligands detected in the buried interface of perovskite films is also inclined to serves as an interface passivators. In conjunction with the above analysis, desired perovskite films with decreased defect density and suppressed non-radiative recombination are acquired for the NH₄SCN sample, leading to impressive power conversion efficiencies of 26.13% with one of the lowest V _OC losses among all reported p-i-n structure PSCs, reaching 96.13% of their theoretical V _OC limit.

A novel additive, parecoxib (Pr), is presented to catalyze α-FAPbI₃ crystallization in the antisolvent-free processes via multinary interactions to the precursor species. This measure provides effective regulation of perovskite crytallization, suppression of δ-FAPbI₃, and passivation of grain boundaries. The as-made Cs-free FAPbI₃ solar cell reaches a high power conversion efficiency (PCE) of 25.38%.

Abstract

Antisolvent-free processes exhibit numerous advantages for fabricating perovskite solar cells (PSCs) while requiring exquisite control of nucleation and crystallization of perovskite film. Without the addition of Cs and Br species, more obstacles are faced for the preferred α-phase pure formamidinium lead triiodide (α-FAPbI₃) to achieve high power conversion efficiency (PCE) and stability. In this work, a novel additive, parecoxib (Pr), is proposed, which catalyzes the direct crystallization of α-FAPbI₃ through multinary interactions with the solvate perovskite precursor. Detailed molecular interactions and in situ analysis reveal that Pr provides nucleation sites, reduces the grain growth rate, suppresses the formation of δ-FAPbI₃, and ultimately enhances the quality of the perovskite film. Furthermore, Pr can in situ passivate the grain boundaries, reduce nonradiative recombination, and enhance open-circuit voltage (V _oc) up to 1.195 V. As a result, high-performance antisolvent-free α-FAPbI₃ PSCs are achieved with the PCE reaching 25.38% and 19.64% for mini-modules (93 cm²). The unencapsulated device maintains 91.08% of the initial PCE for 1000 h at 85 °C, and 90.62% after 1000 h of maximum power point tracking.

A pseudo-halide, short-chain, and hydrophobicity anion PF₆ ⁻ is introduced to form a ligand shell of FAPbI₃ perovskite quantum dot (PQD) to overcome surface defect density, inter-dot transport, and instability challenges, output a record-high efficiency of over 19% and improve long-term stability in PQD solar cells.

Abstract

Metal halide perovskite quantum dots (PQDs), like formamidinium lead triiodide (FAPbI₃), hold significant promise for next-generation photovoltaics. Surface manipulation of PQDs has been extensively reported to be crucial to their photovoltaic performance due to the dynamic binding of capping long-chain ligands. In this work, an efficient surface engineering strategy employing a multifunctional fluorinated pseudo-halide anion ligand, hexafluorophosphate (PF₆ ⁻) is reported for achieving efficient FAPbI₃ PQD solar cells. Leveraging its coordination capability, large ionic radius (2.38 Å), and intrinsic hydrophobicity, PF₆ ⁻ simultaneously passivates iodide vacancies, minimizes inter-dot spacing for enhanced electronic coupling, suppresses ion migration, and provides a hydrophobic barrier. By replacing oleate ligands with PF₆ ⁻ in FAPbI₃ PQDs, an unprecedented high efficiency of 19.01% (17.19% for a 1 cm²-sized device) is achieved, and enhanced storage and operational stability. These findings will provide insight into the design of robust surface structures and low-trap-states PQD films toward high-efficiency and stable solar cells.

A classical p-type liquid crystalline organic semiconductor, 2-decyl-7-phenyl-benzothienobenzothiophene (Ph-BTBT-10), is incorporated into the organic photovoltaic active layer as a dual-functional additive. Its incorporation optimizes the blend morphology with favorable phase separation, extends exciton diffusion length, and significantly improves charge transport dynamics. The binary device based on D18:L8-BO processes using Ph-BTBT-10 yields an impressive power conversion efficiency of 20.3%.

Abstract

Solid additives serve as an effective strategy for modulating the morphology of organic solar cell (OSC) active layers, which critically linked to devices performance. However, current solid additives primarily focus on morphological control, while their inherently weak electrical characteristics may limit improvements in carrier mobility and other electrical properties. This study innovatively introduces a p-type rod-like liquid crystalline (LC) organic-semiconductor, 2-decyl-7-phenylbenzo[b]benzo[4,5]thieno[2,3-d]thiophene (Ph-BTBT-10), as a multifunctional additive in D18:L8-BO-based binary OSCs. Benefiting from its strong π-π stacking and high intrinsic mobility, Ph-BTBT-10 enables precise morphological control while simultaneously improving electrical properties. This dual effect synergistically extends exciton diffusion length, enhances charge separation, suppresses recombination, and significantly boosts hole mobility in blend films. Consequently, the optimized binary devices attained a competitive power conversion efficiency (PCE) of 20.3%, alongside a short-circuit current density of 27.28 mA cm⁻² and fill factor of 80.5%. To the best of knowledge, this performance ranks among the highest reported for binary systems exceeding the 20% PCE threshold. This work demonstrates that p-type LC semiconductors function as multifunctional additives capable of concurrently regulating morphology and boosting intrinsic electrical properties by establishing expanded charge-transport networks, presenting a promising new paradigm for advancing OSC performance.

Nature Photonics, Published online: 22 August 2025; doi:10.1038/s41566-025-01746-6

Coating additive solutions onto wet perovskite films in situ enables flexible all-perovskite tandem solar cells with a certified power conversion efficiency of 23.0% for a module with an aperture area of 20.26 cm2. The modules maintain 97% of their initial efficiency after 10,000 bending cycles with a 10 mm radius.

Inefficient low-molecule-weight LWPM6-based organic solar cells (OSCs) using trimeric acceptor TYT-S are optimized, enhancing power conversion efficiency (PCE) over 20%. LWPM6 flexible devices show excellent mechanical stability and solution-processability, offering new insights for OSCs commercialization.

Abstract

Achieving consistent performance across polymer donor batches is crucial for the commercialization of organic solar cells (OSCs). Compared with high-molecular-weight PM6 (HWPM6), low-molecular-weight PM6 (LWPM6) has lower efficiency but better stress-dispersion characteristics and solution-processability, making its performance improvement vital for practical applications. Here, LWPM6-based OSCs are optimized by introducing a trimeric guest (TYT-S). TYT-S improves PM6:Y6 compatibility, achieving a finer phase separation and a favorable interpenetrating network morphology. A ternary strategy, leveraging molecular electrostatic potential differences, promotes LWPM6 pre-aggregation, extends film-formation time, and enhances molecular ordering. The LWPM6-based ternary system exhibits an optimized vertical phase distribution, with maximum exciton dissociation occurring near the cathode, resulting in a power conversion efficiency (PCE) of 19.23% (LWPM6-based binary with a low PCE of 17.35%). When BTP-eC9 replaces Y6, the LWPM6-based ternary devices achieve a PCE of 20.12% (LWPM6-based binary with a low PCE of 17.64%). Additionally, LW polymers can dissipate stress via segmental motion. After 3000 bending cycles, LWPM6-based flexible devices retain higher initial efficiency than HWPM6-based one, demonstrating better mechanical stability. In mini-modules, they also have good solution-processability. This work demonstrates that a trimer guest strategy can significantly enhance the photovoltaic performance of low-efficiency LWPM6, offering new insights for OSCs commercialization.

Nature Photonics, Published online: 14 August 2025; doi:10.1038/s41566-025-01732-y

This Review covers the latest advances in perovskite/silicon tandem solar cells, with a focus on efficiency, stability and scalability, along with a discussion of outstanding challenges and future directions.

Nature Energy, Published online: 18 August 2025; doi:10.1038/s41560-025-01818-5

A selective templating growth strategy unlocks access to a previously inaccessible class of chemically inert low-dimensional (CI LD) interfaces for the protection of the underlying three-dimensional (3D) perovskite in perovskite solar cells (PSCs). Prototype 1-cm2 3D/CI LD PSCs achieve an efficiency of over 25% and exhibit high operational and thermal stability.

Nature, Published online: 13 August 2025; doi:10.1038/s41586-025-09387-z

A microphase crosslinking strategy, leveraging aziridine-based crosslinkers, is used to render organic thermoelectric materials stretchable and elastic.

Nature Communications, Published online: 09 August 2025; doi:10.1038/s41467-025-62661-6

The efficiency of narrow bandgap subcells is hindered by structural instability and strain accumulation. The authors introduce a rigid sulfonate molecule that suppresses light-induced lattice distortions, enabling certified 29.2% efficiency in all-perovskite tandem solar cells.