Yannan Qian

All-inorganic CsPbI3–xBrx perovskites have emerged as promising photovoltaic materials owing to their excellent thermal stability and tunable bandgap. However, solution-processed CsPbI3–xBrx films continue to suffer from sluggish crystallization kinetics and poor phase stability, which severely limit device performance. Herein, we introduce 6-(trifluoromethyl)–2(3H)-benzothiazolethione (TFMBT) as a multifunctional additive to regulate nucleation and phase transformation. The N–H and C=S groups of TFMBT synergistically weaken the DMSO-[PbI6]4– coordination via hydrogen bonding and Lewis acid–base interactions, facilitating solvent removal and lowering the nucleation barrier. Meanwhile, the CF3 group engages the N–H group of DMA+ in N–H···F contacts, accelerating DMA+ deintercalation and Cs+ incorporation to expedite phase transformation. This synergistic effect cooperatively accelerates the crystallization kinetics, yielding high-quality films with enlarged, uniform grains and suppressed defects. Benefiting from the optimized crystallization regulation and improved film quality, the TFMBT-modified carbon-based CsPbI3–xBrx perovskite solar cells achieve a champion power conversion efficiency of 15.34%, significantly outperforming the control devices (12.75%), along with excellent stability.

We designed a dual-passivation buried interface molecular bridge to connect the SnO ₂ and the CsPbI _x Br _{3− x} layer, achieving a power conversion efficiency of 15.51% for carbon-based all-inorganic perovskite solar cells.

Adding 4-(2-thioureido)benzoic acid (TB) to CsPbI₂Br films enhanced crosslinking, yielding uniform crystal growth and a denser structure, boosting PCE to 13.96%. TB also formed a protective surface barrier, improving device stability.

3-TPT and 4-TPT modified CsPbI ₂ Br, passivating defects and enhancing crystal quality, achieving PCEs of 13.78% and 14.15%. After 500 h at 30% humidity, they retained 81.8% and 85.7% of initial PCE, outperforming the unmodified device’s 50.6%.

Deep-red CsPbI₃ perovskite quantum dots (PeQDs) are essential for high-efficiency perovskite light-emitting diodes (PeLEDs) because of their high color purity and high photoluminescence quantum yield (PLQY). The synergetic strategy of indium (In) doping and chlorine (Cl) surface passivation not only partially replaced Pb²⁺ ions with the smaller ionic In³⁺ but also filled I^- vacancies by Cl^- on the surface, maintaining the humidity stability for more than 24 days and yielding excellent PLQY. Benefiting from this synergetic strategy, deep-red (approximately at 683 nm) CsPbI₃ PeLEDs showed a maximum luminance and external quantum efficiency (EQE) of 311 cd m^-2 and 8.32%, respectively.

A bi-function TiO₂:Yb³⁺/Tm³⁺/Mn²⁺-assisted double-layered photoanode was designed to improve the efficiency of dye-sensitized solar cells (DSSCs). The scanning electron microscopy (SEM) results show that the introduction of Mn²⁺ ions leads to smaller-sized TiO₂:Yb³⁺/Tm³⁺/Mn²⁺ nanospheres, which is changed from nanosheet-shaped TiO₂ and TiO₂:Yb³⁺/Tm³⁺. Based on Scherrer’s formula from the X-ray diffraction (XRD) peak (101), the crystallite sizes decrease due to the introduction of Mn²⁺ ions. By utilizing screen-printing techniques, DSSCs fabricated by bi-function TiO₂:Yb³⁺/Tm³⁺/Mn²⁺-assisted double-layered photoanodes exhibit the short-circuit current density (J_sc) of 15.68 mA/cm², open-circuit voltage (V_oc) of 0.67 V, fill factor (FF) of 0.71 and the power conversion efficiency (PCE) of 7.41%. The PCE of our designed DSSC is higher than that of DSSCs with a TiO₂/TiO₂ photoanode (6.84%), which is attributed to the bi-function effects of TiO₂:Yb³⁺/Tm³⁺/Mn²⁺ including the conversion of NIR into visible light and improved light scattering. An increased charge transfer resistance of the photoanode/electrolyte interface indicates the suppressed charge recombination of electrons with the electrolyte redox couple (I⁻/I₃⁻) in DSSCs with a TiO₂/TiO₂:Yb³⁺/Tm³⁺/Mn²⁺ double-layered photoanode, which also contributes to the enhanced performance of DSSCs. The double-layered photoanode fabricated by bi-function TiO₂:Yb³⁺/Tm³⁺/Mn²⁺ nanospheres will provide a promising avenue for moving DSSCs forward to meet practical applications.