Bin Du

γ-CD-modified PSCs achieve a champion power conversion efficiency of 24.61% with long-term stability.

In this work, a dual-molecular co-modification strategy was developed to construct a multifunctional buried interface layer between SnO ₂ and a perovskite, enabling bilateral defect passivation and stress modulation.

This is a schematic of the intrinsic cyclic degradation of FAPbI ₃ triggered by phase transition. The photoactive α-phase spontaneously transforms into the photoinactive δ-phase under water erosion, driven by reduced Gibbs free energy.

Metal halide perovskites exhibit great application potential in various next-generation optoelectronic devices, and perovskite solar cells (PSCs) have become a core photovoltaic research hotspot owing to their high efficiency and low cost; poor stability and efficiency decay during large-area manufacturing remain key industrial bottlenecks. As a core functional layer, the electron transport layer (ETL) determines the efficiency and stability of PSCs. Tin oxide (SnO2) stands out as an ideal ETL candidate with high electron mobility, wide band gap, low-temperature processability, and superior chemical stability, outperforming traditional materials like TiO2 and ZnO. This review systematically summarizes research advances in SnO2 electron transport layers (SnO2 ETLs) spanning 2020 to 2026, covering their crystal structures, optoelectronic properties, and defect characteristics, fabrication routes (solution-processed, vacuum-deposited, and scalable large-area techniques), modification tactics (elemental doping, surface/interface engineering, and nanostructure modulation), as well as their implementation in various perovskite solar cell architectures, including normal n-i-p structures, inverted p-i-n structures, all-inorganic devices, flexible cells, and large-area photovoltaic modules. It also points out the core challenges in defect control, interfacial stability, and scalable fabrication, and prospects future directions such as synergistic modification, green scalable preparation, and adaptation to lead-free PSCs. This work provides theoretical and technical support for the performance optimization and industrialization of SnO2−based PSCs.

Perovskite solar cells (PSCs) exhibit excellent optoelectronic properties, including a high light absorption coefficient and superior carrier mobility. However, challenges remain in their power conversion efficiency and stability. Intrinsic defects and externally introduced defects exert a key impact on their optoelectronic properties. This paper systematically reviews the core characterization techniques and the latest research progress of perovskite carrier dynamics, with a focus on the structure‐property relationship and regulation strategies between bulk microstructure/interfacial properties and carrier dynamics. Research has shown that interface engineering, defect passivation, and energy level gradient design can effectively optimize carrier transport and separation processes. Optimization strategies such as additive engineering and machine learning assistance are equally crucial. Photon manipulation, low‐cost carbon‐based electrodes, and integrated energy storage systems are also discussed. Techniques including transient absorption spectroscopy (TAS) and time‐resolved photoluminescence (TRPL) have revealed the mechanisms of carrier generation, relaxation, transport, and recombination, providing theoretical guidance for device design. We further explore the carrier dynamics in tandem perovskite devices, flexible perovskite devices, and triple‐mesoporous structures‐these core frontier systems are driving the commercial application of perovskite photovoltaic technology.

Buried interfacial defects, residual strain, and unfavorable energy‐level alignment collectively limit charge extraction and induce nonradiative recombination losses in high‐performance perovskite solar cells (PSCs). Here, we report a multifunctional molecular‐bridge strategy based on 2‐amino‐3‐hydroxybutanoic acid (AHBA) for simultaneous regulation of the SnO ₂ /perovskite buried interface. Benefiting from its synergistic amino, hydroxyl, and carboxyl functional groups, AHBA establishes a cross‐linked interfacial interaction network through coordinated bonding and hydrogen‐bonding interactions, enabling bilateral defect passivation, interfacial strain relaxation, and accelerated electron extraction. The resulting interface exhibits reduced trap density, optimized energy‐level alignment, enhanced crystallographic ordering, and suppressed nonradiative recombination. Ultrafast transient absorption spectroscopy reveals a charge‐carrier extraction time of only 3.5 ps, demonstrating markedly accelerated interfacial charge transfer. The reconstructed electronic landscape further promotes efficient carrier collection and long‐range transport, leading to a champion power conversion efficiency of 26.32% with a fill factor of 85.69% and significantly reduced hysteresis. In addition, the target sample devices retain over 90% of their initial efficiency after 2000 h of storage under ambient conditions and exhibit substantially enhanced thermal stability. This work establishes a molecular‐level design principle that couples defect passivation, strain management, and carrier‐dynamics engineering, providing a versatile route toward highly efficient and durable perovskite photovoltaics.

Single junction perovskite solar cells (PSCs) have surpassed a photoelectric conversion efficiency (PCE) of 27%. However, inevitable interface defects from the preparation process have emerged as notorious barrier to further enhancing performance. In this study, we introduce the L‐isoleucine (L‐lle) to modify the buried interface between tin dioxide (SnO ₂ ) and perovskite in PSCs. The oxygen atoms on the carboxyl group (‐COOH) of L‐lle migrate upward and chemically bond with the uncoordinated lead ions on the perovskite surface, effectively anchoring the displaced lead ions. Concurrently, the downward movement facilitates esterification reaction with the hydroxyl groups (‐OH) on the surface of SnO ₂ , which enhances molecular cross‐linking, expands interface contact, and improves the stability of L‐lle at the buried interface. The efficiency of PSC devices based on L‐lle exhibit a significantly higher efficiency than that of control devices (23.54%), reaching 26.15%. Furthermore, after 1200 h of long‐term stability testing, the modified device can retain 92% of its initial efficiency, demonstrating outstanding operational stability.

This review addresses the scientific challenges of scaling perovskite solar cells from laboratory to industry, as outlined in the graphical It highlights key bottlenecks like film heterogeneity, transport losses, and stability.

This paper systematically reviews the material systems and key functions of ICLs in tandem perovskite solar cells, which build a systematic theoretical framework for ICL research.

This paper summarizes strategies for low-modulus substrate selection, stress-relieving structure design, and flexible interfacial layer development, providing references for strain regulation in perovskite films.