A research team, led by South Korea's Gwangju Institute of Science and Technology (GIST), recently designed a scalable perovskite solar architecture that directly tackles the bottleneck of efficiency loss and instability in larger-area devices. As perovskite cells are scaled up, it becomes increasingly difficult to form a uniform, defect‑free perovskite layer, which leads to enhanced non‑radiative recombination, higher series resistance, and rapid performance degradation under operation.
To overcome this, the researchers re‑engineered the buried electron transport layer (ETL), starting from conventional tin oxide (SnO₂) and incorporating a thin polyethyleneimine (PEI) modifier directly into the SnO₂ during ETL formation. This dual‑function treatment simultaneously improves surface wettability and tunes the SnO₂ work function, which suppresses oxygen‑vacancy defects, establishes favorable interfacial dipoles, and better aligns energy levels with the perovskite absorber.
The result is more efficient electron extraction and highly uniform perovskite crystallization across larger areas, without adding extra processing steps or exotic materials, making the approach compatible with printing‑type, mass‑production methods.
Using PEI‑modified SnO₂ ETLs, the team achieved a power conversion efficiency of 24.49% in small‑area perovskite cells and 22.56% in a mini‑module with a 24.8 cm² active area, placing the module in the top tier of single‑junction perovskite devices at this scale.
The mini‑module retained 94% of its initial efficiency after 500 hours of continuous operation, indicating that interfacial defect suppression and optimized band alignment translate not only into high initial performance but also into improved operational stability.
By providing a simple, solution‑processable interface engineering route that works under ambient‑compatible conditions, this work brings perovskite technology closer to commercially relevant modules where high efficiency, reproducibility over large areas, and durability under real‑world conditions are all essential.
