# Perovskite/silicon tandem solar cell with a distorted SAM interface reaches certified 35.1% efficiency

- Published: 2026-11-05 23:30 UTC
- Section: Power & Energy › Energy
- Tags: perovskite/silicon tandem, 35.1% efficiency, self-assembled monolayer, SAM, textured silicon, π–π stacking, fill factor 85%, ISOS-L-1, certified efficiency, tandem photovoltaics
- URL: https://realtech.media/news/rt-ef354ece4aa6f0b5377f9acc_perovskite_silicon_tandem/

**Authors report a self-assembled monolayer with tailored intramolecular distortion that coats textured silicon conformally and keeps charge transport, in a lab tandem cell.**

![Perovskite/silicon tandem solar cell with a distorted SAM interface reaches certified 35.1% efficiency](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/9162bd489b8010df.png)
*Nature*

A research team reported in Nature a perovskite/silicon tandem solar cell with a certified stabilized power conversion efficiency of 35.1% and a fill factor of 85% [1]. The result was obtained on a laboratory device built on silicon with rough pyramidal textures. The work concerns the design of the self-assembled monolayer (SAM) at the interface between the layers.

## The conjugation trade-off in SAM design

On rough textured substrates, SAM design has been limited by a trade-off. Higher molecular conjugation increases conductivity, but it often leads to unfavourable aggregation that impairs conformal coverage of the surface [1].

The authors propose a rationally engineered molecular spatial conjugation that includes tailored intramolecular distortion. According to the authors, this suppresses excess π–π stacking without sacrificing charge-transport efficiency [1]. They report that this steric regulation produces a highly ordered, conformal SAM across the rough pyramidal textures [1].

## Interface function and device performance

The authors state that the resulting interface provides optimized energy-level alignment for ultrafast charge extraction. They also report improved defect passivation through adaptive conformational adjustment of the molecules, and say the layer serves as a template for growth of a high-quality perovskite film [1].

With this interface, the optimized tandem device reached a fill factor of 85% and a certified stabilized efficiency of 35.1% [1]. In ageing tests under the ISOS-L-1 protocol, the device retained more than 94% of its initial performance after 1,500 hours [1].

The authors present the approach as a molecular engineering route to combine conductivity with film uniformity on textured silicon substrates. The reported figures refer to a single optimized laboratory device, not to a commercial module [1].

## Sources

1. [Nature](https://doi.org/10.1038/s41586-026-11226-8)

---

Source: RealTech, realtech.media — https://realtech.media/news/rt-ef354ece4aa6f0b5377f9acc_perovskite_silicon_tandem/