# Efficient Energy Transfer Down-Shifting Material for Dye-Sensitized Solar Cells

## TL;DR

This paper introduces a new material that improves the performance of dye-sensitized solar cells by efficiently converting harmful UV light into usable visible light.

## Contribution

The novel contribution is the development and characterization of BaSiO3:Eu2+ as an efficient luminescent down-shifting material for solar cells.

## Key findings

- BaSiO3:Eu2+ shows strong UV absorption with peaks near 400 nm and in the 200–300 nm range.
- The material has an optical bandgap of 3.47 eV, suitable for UV absorption.
- A spectral overlap of 2×10^10 M−1cm−1nm4 indicates efficient energy transfer to the N719 dye sensitizer.

## Abstract

Dye-sensitized solar cells (DSSCs) are promising alternatives for power generation due to their environmental friendliness, cost effectiveness, and strong performance under diffused light. Conversely, their low spectral response in the ultraviolet (UV) region significantly obliterates their overall performance. The so-called luminescent down-shifting (LDS) presents a practical solution by converting high-energy UV photons into visible light that can be efficiently absorbed by sensitizer dyes. Herein, a conventional solid-state technique was applied for the synthesis of an LDS, europium (II)-doped barium orthosilicate (BaSiO3:Eu2+) material. The material exhibited strong UV absorption, with prominent peaks near 400 nm and within the 200–300 nm range, despite a weaker response in the visible region. The estimated optical bandgap was 3.47 eV, making it well-suited for UV absorbers. Analysis of the energy transfer mechanism from the LDS material to the N719 dye sensitizer depicted a strong spectral overlap of 2×1010M−1cm−1nm4, suggesting efficient energy transfer from the donor to the acceptor. The estimated Förster distance was approximately 6.83 nm, which matches the absorption profile of the dye-sensitizer. Our findings demonstrate the potential of BaSiO3:Eu2+ as an effective LDS material for enhancing UV light absorption and improving DSSC performance through increased spectral utilization and reduced UV-induced degradation.