# Selective Scatterers Improve Efficiency and Color Neutrality of Semitransparent Photovoltaics

## TL;DR

This paper shows that silicon nanoparticles can improve the efficiency and appearance of semitransparent solar panels by selectively scattering light.

## Contribution

The novel use of dielectric silicon nanoparticles for enhancing both efficiency and color neutrality in semitransparent photovoltaics is introduced.

## Key findings

- Silicon nanoparticles increase photocurrent by 10–15% in luminescent solar concentrators.
- A submonolayer of silicon nanoparticles achieves color neutrality with minimal surface coverage.
- Theoretical predictions align with experimental results using polymer-shell etching.

## Abstract

We demonstrate that dielectric Mie scatterers, in the
form of silicon
nanoparticles (SiNPs), can enhance both the performance and esthetics
of semitransparent photovoltaic devices. Unlike plasmonic metal counterparts,
dielectric SiNPs exhibit lossless, narrow-band, spectral, and spatially
tunable scattering in the visible spectral range. Their effect on
a luminescent solar concentrator (LSC) with high visible light transparency
is analyzed both theoretically and experimentally as a model system.
By selectively reflecting a specific spectral band, SiNPs increase
the optical path length of solar photons within the active layer,
leading to improved absorption and hence device efficiency. Simultaneously,
this light management strategy ensures transmitted color neutrality,
an important requirement for wider acceptance of semitransparent photovoltaics.
Numerical simulations show that in the regime of individual SiNPs
with diameters around 160 nm, a submonolayer surface coverage of ∼10%
is sufficient to achieve color neutrality, at the same time enhancing
photocurrent by 10–15% for an LSC device. Experimentally, such
a dispersed SiNP layer on an LSC substrate is realized by depositing
NPs with the surface capped by a sacrificial polymer shell. Subsequent
etching of the shell by oxygen plasma leads to an LSC device with
a functional selective scattering layer in line with theoretical predictions.