Researchers from Soochow University have conducted a comprehensive simulation study to clarify how pyramid-textured architectures influence the optical and electrical behavior of all-perovskite tandem solar cells (TSCs). With tunable bandgaps, low manufacturing cost, and strong optoelectronic properties, all-perovskite TSCs are among the most promising candidates for next-generation photovoltaics. However, their practical efficiency remains below the theoretical limit - mainly due to insufficient light management and reflection losses in planar designs.
Through a series of coupled optoelectronic simulations, the team examined four distinct textured configurations: a top texture on the wide-bandgap perovskite (WBG-PSK), a middle texture between WBG-PSK and narrow-bandgap perovskite (NBG-PSK), a rear texture beneath the NBG-PSK, and a fully textured design integrating all three. Each configuration was modeled using periodic pyramid patterns to explore how location and feature size impact light absorption and carrier generation.
The results show that front-side textures with smaller pyramid dimensions significantly enhance short-wavelength absorption, leading to improved photocurrent in the WBG sub-cell. In contrast, rear-side textures with larger structural features strengthen long-wavelength light-trapping, improving the NBG sub-cell’s performance. The middle-layer texture, by comparison, produced only minor changes, with photocurrent density fluctuations under 0.5 mA/cm² - confirming its limited optical impact.
Integrating all textures in a fully structured device achieved the best overall optical enhancement, yielding a photocurrent density (Jph) of 17.59 mA/cm² through effective current matching and reducing reflection losses to just 3.60 mA/cm². Electrical modeling further indicated that efficiency variations among the different designs are predominantly driven by optical effects rather than electrical limitations.
This work provides guidance for designing advanced textured all-perovskite TSCs. It highlights that precise control over texture size and placement can substantially boost both sub-cell performance and overall efficiency, offering a potential pathway toward next-generation perovskite tandem photovoltaics with superior light-management characteristics.
