Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells

Research output: Contribution to journalArticleResearchpeer review

Authors

  • Leon Salomon
  • Michael Rienäcker
  • Yevgeniya Larionova
  • Alexej Haller
  • Sarah Spätlich
  • Robby Peibst
  • Jan Krügener

External Research Organisations

  • Karlsruhe Institute of Technology (KIT)
  • Institute for Solar Energy Research (ISFH)
View graph of relations

Details

Original languageEnglish
Article numbere202500483
JournalSolar RRL
Volume9
Issue number22
Publication statusPublished - 24 Nov 2025

Abstract

In this work we present an optimized process for the photolithographic fabrication of inverted pyramid photonic crystals (PC) with 3.1 µm periodicity on Si(001)-substrates to improve the light trapping in single junction solar cells. Anisotropic alkaline etch was used to form the pyramids with (111)-sidewalls using partial surface masking with lithographically structured SiO2. Ridge widths between the pyramids down to (150 ± 50) nm were achieved, while ensuring a yield of multiple (2 × 2) cm2 areas per wafer sample. After deposition of an antireflection stack consisting of AlOx, SiNy, and SiOz with different thickness optimizations a weighted reflection approaching that of a random pyramid reference sample could be shown. We demonstrate a path length enhancement of 25 at a wavelength of 1200 nm for our cell with PCs. This is en par with but not superior to the respective value for the reference sample with random pyramids, and still below the Lambertian limit. Furthermore, we present the first POLO2-IBC (interdigitated back contact) solar cells with such photonic crystals on the front sides. These solar cells feature a power conversion efficiency of 22.9%.

Keywords

    interdigitated back contact solar cells, inverted pyramids, photolithography, photonic crystals

ASJC Scopus subject areas

Cite this

Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells. / Salomon, Leon; Rienäcker, Michael; Larionova, Yevgeniya et al.
In: Solar RRL, Vol. 9, No. 22, e202500483, 24.11.2025.

Research output: Contribution to journalArticleResearchpeer review

Salomon, L, Rienäcker, M, Larionova, Y, Haller, A, Spätlich, S, Peibst, R & Krügener, J 2025, 'Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells', Solar RRL, vol. 9, no. 22, e202500483. https://doi.org/10.1002/solr.202500483
Salomon, L., Rienäcker, M., Larionova, Y., Haller, A., Spätlich, S., Peibst, R., & Krügener, J. (2025). Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells. Solar RRL, 9(22), Article e202500483. https://doi.org/10.1002/solr.202500483
Salomon L, Rienäcker M, Larionova Y, Haller A, Spätlich S, Peibst R et al. Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells. Solar RRL. 2025 Nov 24;9(22):e202500483. doi: 10.1002/solr.202500483
Salomon, Leon ; Rienäcker, Michael ; Larionova, Yevgeniya et al. / Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells. In: Solar RRL. 2025 ; Vol. 9, No. 22.
Download
@article{dd7d31ec754d48a0b0e4111adea9e113,
title = "Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells",
abstract = "In this work we present an optimized process for the photolithographic fabrication of inverted pyramid photonic crystals (PC) with 3.1 µm periodicity on Si(001)-substrates to improve the light trapping in single junction solar cells. Anisotropic alkaline etch was used to form the pyramids with (111)-sidewalls using partial surface masking with lithographically structured SiO2. Ridge widths between the pyramids down to (150 ± 50) nm were achieved, while ensuring a yield of multiple (2 × 2) cm2 areas per wafer sample. After deposition of an antireflection stack consisting of AlOx, SiNy, and SiOz with different thickness optimizations a weighted reflection approaching that of a random pyramid reference sample could be shown. We demonstrate a path length enhancement of 25 at a wavelength of 1200 nm for our cell with PCs. This is en par with but not superior to the respective value for the reference sample with random pyramids, and still below the Lambertian limit. Furthermore, we present the first POLO2-IBC (interdigitated back contact) solar cells with such photonic crystals on the front sides. These solar cells feature a power conversion efficiency of 22.9%.",
keywords = "interdigitated back contact solar cells, inverted pyramids, photolithography, photonic crystals",
author = "Leon Salomon and Michael Rien{\"a}cker and Yevgeniya Larionova and Alexej Haller and Sarah Sp{\"a}tlich and Robby Peibst and Jan Kr{\"u}gener",
note = "Publisher Copyright: {\textcopyright} 2025 The Author(s). Solar RRL published by Wiley-VCH GmbH.",
year = "2025",
month = nov,
day = "24",
doi = "10.1002/solr.202500483",
language = "English",
volume = "9",
number = "22",

}

Download

TY - JOUR

T1 - Optimization of Photolithographic Fabrication of Photonic Crystals and their Use in High Efficiency Solar Cells

AU - Salomon, Leon

AU - Rienäcker, Michael

AU - Larionova, Yevgeniya

AU - Haller, Alexej

AU - Spätlich, Sarah

AU - Peibst, Robby

AU - Krügener, Jan

N1 - Publisher Copyright: © 2025 The Author(s). Solar RRL published by Wiley-VCH GmbH.

PY - 2025/11/24

Y1 - 2025/11/24

N2 - In this work we present an optimized process for the photolithographic fabrication of inverted pyramid photonic crystals (PC) with 3.1 µm periodicity on Si(001)-substrates to improve the light trapping in single junction solar cells. Anisotropic alkaline etch was used to form the pyramids with (111)-sidewalls using partial surface masking with lithographically structured SiO2. Ridge widths between the pyramids down to (150 ± 50) nm were achieved, while ensuring a yield of multiple (2 × 2) cm2 areas per wafer sample. After deposition of an antireflection stack consisting of AlOx, SiNy, and SiOz with different thickness optimizations a weighted reflection approaching that of a random pyramid reference sample could be shown. We demonstrate a path length enhancement of 25 at a wavelength of 1200 nm for our cell with PCs. This is en par with but not superior to the respective value for the reference sample with random pyramids, and still below the Lambertian limit. Furthermore, we present the first POLO2-IBC (interdigitated back contact) solar cells with such photonic crystals on the front sides. These solar cells feature a power conversion efficiency of 22.9%.

AB - In this work we present an optimized process for the photolithographic fabrication of inverted pyramid photonic crystals (PC) with 3.1 µm periodicity on Si(001)-substrates to improve the light trapping in single junction solar cells. Anisotropic alkaline etch was used to form the pyramids with (111)-sidewalls using partial surface masking with lithographically structured SiO2. Ridge widths between the pyramids down to (150 ± 50) nm were achieved, while ensuring a yield of multiple (2 × 2) cm2 areas per wafer sample. After deposition of an antireflection stack consisting of AlOx, SiNy, and SiOz with different thickness optimizations a weighted reflection approaching that of a random pyramid reference sample could be shown. We demonstrate a path length enhancement of 25 at a wavelength of 1200 nm for our cell with PCs. This is en par with but not superior to the respective value for the reference sample with random pyramids, and still below the Lambertian limit. Furthermore, we present the first POLO2-IBC (interdigitated back contact) solar cells with such photonic crystals on the front sides. These solar cells feature a power conversion efficiency of 22.9%.

KW - interdigitated back contact solar cells

KW - inverted pyramids

KW - photolithography

KW - photonic crystals

UR - http://www.scopus.com/inward/record.url?scp=105017405206&partnerID=8YFLogxK

U2 - 10.1002/solr.202500483

DO - 10.1002/solr.202500483

M3 - Article

AN - SCOPUS:105017405206

VL - 9

JO - Solar RRL

JF - Solar RRL

SN - 2367-198X

IS - 22

M1 - e202500483

ER -

By the same author(s)