Manipulating Buried Interface via Aromatic Amino Acid Derivatives for Wide‐Bandgap Perovskite Solar Cells and Tandem Devices

Why It Matters

The interface engineering lifts both efficiency and long‑term stability of wide‑bandgap perovskites, a critical bottleneck for high‑performance tandem solar modules and commercial solar‑energy adoption.

Key Takeaways

• NBP molecule passivates Pb2+ and iodine vacancies at buried interface
• Interface engineering raises WBG perovskite PCE to 20.81% with 1.371 V V_OC
• Modified cells retain 85.3% efficiency after 1000 h MPPT testing
• Two‑terminal tandem device reaches 29.05% efficiency using NBP‑modified subcell
• Electrostatic and π‑π stacking improve energy alignment between Me‑4PACz and perovskite

Pulse Analysis

Perovskite photovoltaics have surged ahead of traditional silicon, yet wide‑bandgap (WBG) subcells remain hampered by voltage losses and interfacial defects. The buried interface, where the hole‑transport layer meets the perovskite absorber, is a hotspot for non‑radiative recombination, especially when uncoordinated lead ions and halide vacancies proliferate. By inserting the aromatic amino‑acid derivative NBP, researchers exploit both electrostatic attraction and π‑π stacking to create a chemically robust interlayer that simultaneously passivates these defects and fine‑tunes energy‑level alignment, addressing a long‑standing efficiency ceiling.

The performance uplift is striking: the NBP‑modified WBG perovskite cell reaches a certified 20.81% power‑conversion efficiency, driven by a record‑high open‑circuit voltage of 1.371 V. Moreover, the device demonstrates remarkable photostability, preserving 85.3% of its initial output after 1,000 hours of continuous maximum‑power‑point tracking—a benchmark that rivals the durability of mature silicon technologies. Compared with prior interface‑passivation strategies, the NBP approach delivers a more pronounced reduction in defect density without compromising film morphology, suggesting a scalable pathway for manufacturing.

When paired with a 1.25 eV narrow‑bandgap counterpart, the NBP‑engineered subcell enables a two‑terminal tandem architecture that pushes overall efficiency to 29.05%, edging closer to the theoretical Shockley‑Queisser limit for tandem devices. This breakthrough not only underscores the commercial viability of all‑perovskite tandems but also signals a broader shift toward molecular‑level interface design as a cornerstone of next‑generation solar technology. Continued optimization of such buried‑layer chemistries could accelerate large‑scale deployment, driving down levelized cost of electricity and expanding the role of photovoltaics in the global energy transition.