TaS2 back contact improving oxide-converted Cu2BaSnS4 solar cells

Andrea Crovetto*, Kristine Børsting, Rasmus Nielsen, Alireza Hajijafarassar, Ole Hansen, Brian Seger, Ib Chorkendorff, Peter C.K. Vesborg

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Solar cells based on the wide band-gap Cu2BaSnS4 (CBTS) photoabsorber have achieved open circuit voltages up to 1.1 V over a short development period, making CBTS an attractive material for tandem photovoltaic and photoelectrochemical cells. In this work, we explore an alternative CBTS growth route based on oxide precursors, and we propose TaS2 as an alternative back contact material to the commonly used Mo/MoS2. The oxide precursor route does not require higher sulfurization temperatures than other more common fabrication routes, and it yields CBTS films with negligible Stokes shift between photoluminescence maximum and band gap energy, while at the same time avoiding sulfur contamination of vacuum systems. The high work-function metallic TaS2 compound is selected as a prospective hole-selective contact, which could also prevent the losses associated with carrier transport across the semiconducting MoS2 layer. By comparing CBTS solar cells with Mo and TaS2 back contacts, the latter shows a significantly lower series resistance, resulting in a 10% relative efficiency improvement. Finally, we fabricate a proof-of-concept monolithic CBTS/Si tandem cell using a thin Ti(O,N) interlayer intended both as a diffusion barrier and as a recombination layer between the two subcells.
Original languageEnglish
JournalApplied Energy Materials
ISSN2574-0962
DOIs
Publication statusAccepted/In press - 2020

Cite this

@article{e9e757f31e724c8599d85cf26fd576e7,
title = "TaS2 back contact improving oxide-converted Cu2BaSnS4 solar cells",
abstract = "Solar cells based on the wide band-gap Cu2BaSnS4 (CBTS) photoabsorber have achieved open circuit voltages up to 1.1 V over a short development period, making CBTS an attractive material for tandem photovoltaic and photoelectrochemical cells. In this work, we explore an alternative CBTS growth route based on oxide precursors, and we propose TaS2 as an alternative back contact material to the commonly used Mo/MoS2. The oxide precursor route does not require higher sulfurization temperatures than other more common fabrication routes, and it yields CBTS films with negligible Stokes shift between photoluminescence maximum and band gap energy, while at the same time avoiding sulfur contamination of vacuum systems. The high work-function metallic TaS2 compound is selected as a prospective hole-selective contact, which could also prevent the losses associated with carrier transport across the semiconducting MoS2 layer. By comparing CBTS solar cells with Mo and TaS2 back contacts, the latter shows a significantly lower series resistance, resulting in a 10{\%} relative efficiency improvement. Finally, we fabricate a proof-of-concept monolithic CBTS/Si tandem cell using a thin Ti(O,N) interlayer intended both as a diffusion barrier and as a recombination layer between the two subcells.",
author = "Andrea Crovetto and Kristine B{\o}rsting and Rasmus Nielsen and Alireza Hajijafarassar and Ole Hansen and Brian Seger and Ib Chorkendorff and Vesborg, {Peter C.K.}",
year = "2020",
doi = "10.1021/acsaem.9b02251",
language = "English",
journal = "Applied Energy Materials",
issn = "2574-0962",
publisher = "ACS Publications",

}

TaS2 back contact improving oxide-converted Cu2BaSnS4 solar cells. / Crovetto, Andrea; Børsting, Kristine; Nielsen, Rasmus; Hajijafarassar, Alireza; Hansen, Ole; Seger, Brian; Chorkendorff, Ib; Vesborg, Peter C.K.

In: Applied Energy Materials, 2020.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - TaS2 back contact improving oxide-converted Cu2BaSnS4 solar cells

AU - Crovetto, Andrea

AU - Børsting, Kristine

AU - Nielsen, Rasmus

AU - Hajijafarassar, Alireza

AU - Hansen, Ole

AU - Seger, Brian

AU - Chorkendorff, Ib

AU - Vesborg, Peter C.K.

PY - 2020

Y1 - 2020

N2 - Solar cells based on the wide band-gap Cu2BaSnS4 (CBTS) photoabsorber have achieved open circuit voltages up to 1.1 V over a short development period, making CBTS an attractive material for tandem photovoltaic and photoelectrochemical cells. In this work, we explore an alternative CBTS growth route based on oxide precursors, and we propose TaS2 as an alternative back contact material to the commonly used Mo/MoS2. The oxide precursor route does not require higher sulfurization temperatures than other more common fabrication routes, and it yields CBTS films with negligible Stokes shift between photoluminescence maximum and band gap energy, while at the same time avoiding sulfur contamination of vacuum systems. The high work-function metallic TaS2 compound is selected as a prospective hole-selective contact, which could also prevent the losses associated with carrier transport across the semiconducting MoS2 layer. By comparing CBTS solar cells with Mo and TaS2 back contacts, the latter shows a significantly lower series resistance, resulting in a 10% relative efficiency improvement. Finally, we fabricate a proof-of-concept monolithic CBTS/Si tandem cell using a thin Ti(O,N) interlayer intended both as a diffusion barrier and as a recombination layer between the two subcells.

AB - Solar cells based on the wide band-gap Cu2BaSnS4 (CBTS) photoabsorber have achieved open circuit voltages up to 1.1 V over a short development period, making CBTS an attractive material for tandem photovoltaic and photoelectrochemical cells. In this work, we explore an alternative CBTS growth route based on oxide precursors, and we propose TaS2 as an alternative back contact material to the commonly used Mo/MoS2. The oxide precursor route does not require higher sulfurization temperatures than other more common fabrication routes, and it yields CBTS films with negligible Stokes shift between photoluminescence maximum and band gap energy, while at the same time avoiding sulfur contamination of vacuum systems. The high work-function metallic TaS2 compound is selected as a prospective hole-selective contact, which could also prevent the losses associated with carrier transport across the semiconducting MoS2 layer. By comparing CBTS solar cells with Mo and TaS2 back contacts, the latter shows a significantly lower series resistance, resulting in a 10% relative efficiency improvement. Finally, we fabricate a proof-of-concept monolithic CBTS/Si tandem cell using a thin Ti(O,N) interlayer intended both as a diffusion barrier and as a recombination layer between the two subcells.

U2 - 10.1021/acsaem.9b02251

DO - 10.1021/acsaem.9b02251

M3 - Journal article

JO - Applied Energy Materials

JF - Applied Energy Materials

SN - 2574-0962

ER -