The development of high-performance, stable quantum dot (QD) inks is critical yet challenging for advancing the efficiency and scalability of next-generation solution-processed optoelectronic devices. Inorganic lead iodide ligands passivated lead sulfide QDs (PbS-PbI₂) have been attractive for their superior surface passivation and strong inter-dot coupling. However, the state-of-the-art inks typically require strongly coordinating alkylamine solvents to dissociate and solvate the PbI₂ ligand, yet these solvents can continuously etch the QDs, leading to rapid ink degradation within a few hours. Herein, an amine-vapor pre-solvation strategy is proposed using a facile butylamine (BA) vapor (<10 min) pretreatment of QDs, enabling stable dispersion of QDs in BA-free solvents (e.g., N-methyl-2-pyrrolidone (NMP) and propylene carbonate). The resulting QD inks remain stable for >60 days with no variation in QD size, while QD films exhibit reduced trap-related losses. Solar cells processed from 60-day-aged NMP inks retain 90% of their initial power conversion efficiency (12.1%), whereas BA-based inks degrade within hours, reducing their device efficiency from 11% to 0.3% after only 4 hours of aging. The shelf-stable NMP ink further enables large-area blade-coating of uniform PbS-PbI₂ films, manifesting the potential in scalable manufacturing of high-performance QD optoelectronic devices.

Lead sulfide quantum dots (PbS QDs) are promising for near-infrared photovoltaics due to their large exciton Bohr radius and size-tunable bandgap. However, extending absorption into the near-infrared (bandgap < 1.13 eV) necessitates larger QDs, which weakens quantum confinement and lowers the conduction band (CB) energy towards bulk-like levels. This CB shift induces severe energy-level misalignment at the ZnO/QDs heterojunction interface, impeding charge extraction efficiency. Conventional dipole-based energy-level tuning strategies rely on ligands coordinated to Pb sites. However, large PbS QDs expose more non-polar (100) facets with a stoichiometric 1:1 Pb:S ratio, where traditional ligands fail to bind S sites, presenting a fundamental barrier to precise energy-level control. To address this issue, we introduce a novel approach: modulating PbS QD energy levels by inducing interfacial dipoles through direct metal cation coordination to the S sites. Systematic screening of metal salts revealed that Zn²⁺ coordination induces the most prominent dipole effect, reducing the work function (WF) of PbS QDs from 4.38 to 4.28 eV. This optimization aligns the band arrangement at the ZnO/QDs interface and facilitates efficient extraction of photogenerated electrons from the PbS absorber layer to the ZnO electron transport layer (ETL). Solar cell devices fabricated using this strategy achieved a power conversion efficiency (PCE) of 11.0%, representing a 12% relative enhancement over the control group (9.8%).

Photothermal CO₂ reduction with H₂O, integrating advantages of photocatalysis driven H₂O splitting and thermal catalysis promoted CO₂ reduction, has drawn sharply increasing attention in artificial synthesis of solar fuels. The photothermal effect of metal nanoparticles facilities CO₂ hydrogenation and activation of lattice oxygen in oxide photocatalyst promotes H₂O oxidation, which is essentially considered for highly efficient photothermal catalysis. However, the large thermal conductivity of most metal nanoparticles induces inevitable heat dissipation, restricting the increase of catalyst temperature. In this work, to minimize the heat dissipation, we employ bismuth nanoparticles as photothermal unit, which is of the lowest thermal conductivity in the metal family. Meanwhile, we adopt bismuth doped NaTaO₃ as photocatalytic unit because of the bismuth doping induced activation of lattice oxygen. The bismuth nanoparticles are assembled with bismuth doped NaTaO₃ through one-step tunable transformation from Bi₄TaO₈Cl. Benefiting from the photothermal effect, thermal insulation caused by bismuth metal, and lattice oxygen activation by bismuth doping, the NaTaO₃:Bi hybrid exhibits high photothermal catalytic performance. The yield of CO over NaTaO₃:Bi hybrid at 413 K via photothermal catalysis is 141 times higher than that room temperature photocatalysis. Further, ultraviolet (UV) light irradiation leads to 89.2% selectivity of CO and visible light irradiation leads to 97.5% selectivity of CH₄. This work may broaden the photocatalytic application of ABO₃ perovskite and provides a novel strategy for the development of photothermal catalysts for artificial photosynthesis.