# 2D Ruddlesden–Popper Perovskites with Polymer Additive as Stable and Transparent Optoelectronic Materials for Building-Integrated Applications

## TL;DR

This paper explores 2D perovskites with a polymer additive as stable, transparent materials for use in building-integrated optoelectronics.

## Contribution

The study introduces polymer-enhanced 2D perovskites with high transparency and stability for building-integrated applications.

## Key findings

- 2D RP perovskite films with PVP show over 50% visible transmittance and stability under heat and light for 100 hours.
- 2D RP films retain their phase after aging, unlike 3D perovskites which show structural degradation.
- 2D DJ films with PVP have a bandgap up to 2.95 eV, over 70% transmittance, and smooth surfaces (~2 nm roughness).

## Abstract

We report on the use of 2D Ruddlesden–Popper (RP) perovskites as optoelectronic materials in building-integrated applications, addressing the challenge of balancing transparency, photoluminescence, and stability. With the addition of polyvinylpyrrolidone (PVP), the 2D RP films exhibit superior transparency compared to their 3D counterparts with an average visible transmittance (AVT) greater than 50% and photoluminescence stability under continuous illumination and 85 °C heat for up to 100 h as bare, unencapsulated films. Structural investigations show a stress relaxation in the 3D perovskite films after degradation from thermal aging that is not observed in the 2D RP films, which retain their phase after thermal and light aging. We also demonstrate ultrasmooth, wide-bandgap 2D Dion–Jacobson (DJ) films with PVP incorporation up to 2.95 eV, an AVT above 70%, and roughnesses of ~2 nm. These findings contribute to the development of next-generation solar materials, paving the way for their integration into built structures.