Lirong Dong

Flexible lead‐halide perovskite solar modules with carbon electrodes (C‐fPSMs) are promising for printed photovoltaics due to their low cost and compatibility with roll‐to‐roll (R2R) fabrication. However, the mechanical fragility of microcrystalline perovskite films, arising from their high grain‐boundary density, limits their practical application. Here, we report a vapor‐phase grain‐boundary anchoring strategy via thiol vapor annealing to molecularly toughen printed perovskite layers. Thiol molecules interact with intermediate species and preferentially anchor at surfaces and grain boundaries, reprogramming crystallization across the film. This chemomechanical conditioning promotes grain growth, reduces trap density, and transforms the deformation behavior from brittle fracture to ductile strain accommodation, as evidenced by reduced Young's modulus, increased yield strain, and significantly enhanced fracture toughness. As a result, treated devices retain 93% of their initial performance after 25 000 bending cycles, representing a new benchmark for flexible perovskite cells. In addition, improved film uniformity and interfacial contact enable power conversion efficiencies of 15.7% for R2R‐printed cells and 12.1% for modules (20.25 cm ² ), with scalability demonstrated up to 900 cm ² (17.26%). This work provides a scalable strategy to simultaneously enhance mechanical robustness and photovoltaic performance.

Flexible lead‐halide perovskite solar modules with carbon electrodes (C‐fPSMs) are promising for printed photovoltaics due to their low cost and compatibility with roll‐to‐roll (R2R) fabrication. However, the mechanical fragility of microcrystalline perovskite films, arising from their high grain‐boundary density, limits their practical application. Here, we report a vapor‐phase grain‐boundary anchoring strategy via thiol vapor annealing to molecularly toughen printed perovskite layers. Thiol molecules interact with intermediate species and preferentially anchor at surfaces and grain boundaries, reprogramming crystallization across the film. This chemomechanical conditioning promotes grain growth, reduces trap density, and transforms the deformation behavior from brittle fracture to ductile strain accommodation, as evidenced by reduced Young's modulus, increased yield strain, and significantly enhanced fracture toughness. As a result, treated devices retain 93% of their initial performance after 25 000 bending cycles, representing a new benchmark for flexible perovskite cells. In addition, improved film uniformity and interfacial contact enable power conversion efficiencies of 15.7% for R2R‐printed cells and 12.1% for modules (20.25 cm ² ), with scalability demonstrated up to 900 cm ² (17.26%). This work provides a scalable strategy to simultaneously enhance mechanical robustness and photovoltaic performance.

Ligand engineering is an effective method to reduce defects in perovskite solar cells (PSCs) and to enhance efficiency.

Guided by phase-field simulations, a pre-coated 2D perovskite layer enables the growth of void-free perovskite layers over one-micron-thick, achieving high-efficiency, fully printed solar cells.

Recently, organic photovoltaics (OPV) have achieved power conversion efficiencies (PCE) above 20% thus coming closer to market entry. Building-integrated photovoltaics (BIPV) and building-attached photovoltaics (BAPV) are two key areas where the functional advantages of both OPV and BIPV/BAPV complement each other and thus could pave the way for market penetration of OPV. Herein, we report on large-area, all-solution-processed flexible OPV modules manufactured by a fully roll-to-roll (R2R) method with high levels of process repeatability. The OPV modules show an accelerated lifetime (ALT) of more than 1000 h and 2800 h under the ISOS-L2 and ISOS-D3 testing conditions, respectively. Long-term outdoor monitoring of the OPV modules was conducted in a typical central European climate, considering two distinct mounting angles that hold significant relevance for BIPV installations i.e., 45° inclination with respect to the ground (representing the optimal tilt angle of the site) and 90° vertical mounting (as mostly encountered in BIPV façades). The ISOS-O2 protocol was used as the test standard for outdoor monitoring. The results show that the OPV modules can offer higher daily specific energy yields (Y_FD), i.e., higher ratios of daily energy yield and STC W_P capacity of the module, than a reference mono-crystalline (m-Si) module for BIPV installations typical of a rooftop case (i.e., 45°), whereas for façade integrated cases (i.e., 90°), OPV modules offer Y_FD values identical to that of m-Si modules. Detailed laboratory investigations reveal that the higher Y_FD values of the OPV modules at 45° mounting stems from their negligible temperature coefficient of -0.008 %/°C, whereas at 90° mounting, the angle-dependent response of the modules plays a crucial role.

The growing demand for sustainable energy solutions has made the development of scalable, efficient, and cost‐effective perovskite solar cells (PSCs) increasingly important. Wide‐bandgap perovskites (WB‐PSCs) stand out due to their efficiency in low‐light conditions and their use in tandem solar cells. WB‐PSCs are currently behind conventional PSCs in upscaling, with limited success in printing wide bandgap PSCs. Developing upscaling methods is essential to fully realize their potential in the renewable energy sector. This research addresses the development of roll‐to‐roll (R2R) slot‐die coating of Cs_0.05FA_0.95PbBr₃‐based WB‐PSCs by focusing on improving the film formation process and ink formulation. By adding optimal concentration of CsBr and performing in situ characterization, we obtained Cs_0.05FA_0.95PbBr₃ films with enhanced morphology and crystallinity in ambient conditions (50% RH), without inducing secondary phase formation. In addition, slot‐die coating defects are eliminated through introducing DMSO: Butanol (9:1) solvent system. The R2R coated wide‐bandgap PSCs reaches a power conversion efficiency (PCE) of up to 8.97% under 1‐sun conditions and 18.3% PCE under indoor conditions. The corresponding R2R coated modules with a 5 × 5 cm² active area achieve a PCE of 5.8%, representing a crucial step towards the high‐throughput, cost‐effective production of perovskite solar modules.

SAM enabled and simplified fully printed carbon-based flexible perovskite modules.

Fully printed carbon-based flexible perovskite module with an efficiency of 11.6%.