Development of Arsenic Doped Cd(Se,Te) Absorbers by MOCVD for Thin Film Solar Cells

Ochai Oklobia; Giray Kartopu; Stephen Jones; Peter Siderfin; B. Grew; Harrison Ka Hin Lee; W. Tsoi; Ali Abbas; John Walls; Deborah McGott; Matthew Reese; S. J. C. Irvine

doi:10.1016/j.solmat.2021.111325

Development of Arsenic Doped Cd(Se,Te) Absorbers by MOCVD for Thin Film Solar Cells

Ochai Oklobia, Giray Kartopu, Stephen Jones, Peter Siderfin, B. Grew, Harrison Ka Hin Lee, W. Tsoi, Ali Abbas, John Walls, Deborah McGott, Matthew Reese, S. J. C. Irvine

Materials Science

Research output: Contribution to journal › Article › peer-review

12 Scopus Citations

Abstract

Recent developments in CdTe solar cell technology have included the incorporation of ternary alloy Cd(Se,Te) in the devices. CdTe absorber band gap grading due to Se alloying contributes to current density enhancement and can result in device performance improvement. Here we report Cd(Se,Te) polycrystalline thin films grown by a chamberless inline atmospheric pressure metal organic chemical vapour deposition technique, with subsequent incorporation in CdTe solar cells. The compositional dependence of the crystal structure and optical properties of Cd(Se,Te) are examined. Selenium graded Cd(Se,Te)/CdTe absorber structure in devices are demonstrated using either a single CdSe layer or CdSe/Cd(Se,Te) bilayer (with or without As doping in the Cd(Se,Te) layer). Cross-sectional TEM/EDS, photoluminescence spectra and secondary ion mass spectroscopy analysis confirmed the formation of a graded Se profile toward the back contact with a diffusion length of ~1.5 μm and revealed back-diffusion of Group V (As) dopants from the CdTe layer into Cd(Se,Te) grains. Due to the strong Se/Te interdiffusion, CdSe in the Se bilayer configuration was unable to form an n-type emitter layer in processed devices. In situ As doping of the Cd(Se,Te) layer benefited the device junction quality with current density reaching 28.3 mA/cm². The results provide useful insights for the optimisation of Cd(Se,Te)/CdTe solar cells.

Original language	American English
Article number	Article No. 111325
Number of pages	11
Journal	Solar Energy Materials and Solar Cells
Volume	231
DOIs	https://doi.org/10.1016/j.solmat.2021.111325 https://doi.org/10.1016/j.solmat.2021.111325
State	Published - Oct 2021

Bibliographical note

Publisher Copyright:
© 2021

NREL Publication Number

NREL/JA-5K00-79902

Keywords

As doping
Cd(Se,Te)
CdSe
CdTe
MOCVD
Photovoltaics
Solar cells
Thin film

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

https://www.nrel.gov/docs/fy21osti/79902.pdf

Cite this

Oklobia, O., Kartopu, G., Jones, S., Siderfin, P., Grew, B., Lee, H. K. H., Tsoi, W., Abbas, A., Walls, J., McGott, D., Reese, M., & Irvine, S. J. C. (2021). Development of Arsenic Doped Cd(Se,Te) Absorbers by MOCVD for Thin Film Solar Cells. Solar Energy Materials and Solar Cells, 231, Article Article No. 111325. https://doi.org/10.1016/j.solmat.2021.111325, https://doi.org/10.1016/j.solmat.2021.111325

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title = "Development of Arsenic Doped Cd(Se,Te) Absorbers by MOCVD for Thin Film Solar Cells",

abstract = "Recent developments in CdTe solar cell technology have included the incorporation of ternary alloy Cd(Se,Te) in the devices. CdTe absorber band gap grading due to Se alloying contributes to current density enhancement and can result in device performance improvement. Here we report Cd(Se,Te) polycrystalline thin films grown by a chamberless inline atmospheric pressure metal organic chemical vapour deposition technique, with subsequent incorporation in CdTe solar cells. The compositional dependence of the crystal structure and optical properties of Cd(Se,Te) are examined. Selenium graded Cd(Se,Te)/CdTe absorber structure in devices are demonstrated using either a single CdSe layer or CdSe/Cd(Se,Te) bilayer (with or without As doping in the Cd(Se,Te) layer). Cross-sectional TEM/EDS, photoluminescence spectra and secondary ion mass spectroscopy analysis confirmed the formation of a graded Se profile toward the back contact with a diffusion length of ~1.5 μm and revealed back-diffusion of Group V (As) dopants from the CdTe layer into Cd(Se,Te) grains. Due to the strong Se/Te interdiffusion, CdSe in the Se bilayer configuration was unable to form an n-type emitter layer in processed devices. In situ As doping of the Cd(Se,Te) layer benefited the device junction quality with current density reaching 28.3 mA/cm2. The results provide useful insights for the optimisation of Cd(Se,Te)/CdTe solar cells.",

keywords = "As doping, Cd(Se,Te), CdSe, CdTe, MOCVD, Photovoltaics, Solar cells, Thin film",

author = "Ochai Oklobia and Giray Kartopu and Stephen Jones and Peter Siderfin and B. Grew and Lee, {Harrison Ka Hin} and W. Tsoi and Ali Abbas and John Walls and Deborah McGott and Matthew Reese and Irvine, {S. J. C.}",

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doi = "10.1016/j.solmat.2021.111325",

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Oklobia, O, Kartopu, G, Jones, S, Siderfin, P, Grew, B, Lee, HKH, Tsoi, W, Abbas, A, Walls, J, McGott, D, Reese, M & Irvine, SJC 2021, 'Development of Arsenic Doped Cd(Se,Te) Absorbers by MOCVD for Thin Film Solar Cells', Solar Energy Materials and Solar Cells, vol. 231, Article No. 111325. https://doi.org/10.1016/j.solmat.2021.111325, https://doi.org/10.1016/j.solmat.2021.111325

TY - JOUR

T1 - Development of Arsenic Doped Cd(Se,Te) Absorbers by MOCVD for Thin Film Solar Cells

AU - Oklobia, Ochai

AU - Kartopu, Giray

AU - Jones, Stephen

AU - Siderfin, Peter

AU - Grew, B.

AU - Lee, Harrison Ka Hin

AU - Tsoi, W.

AU - Abbas, Ali

AU - Walls, John

AU - McGott, Deborah

AU - Reese, Matthew

AU - Irvine, S. J. C.

PY - 2021/10

Y1 - 2021/10

N2 - Recent developments in CdTe solar cell technology have included the incorporation of ternary alloy Cd(Se,Te) in the devices. CdTe absorber band gap grading due to Se alloying contributes to current density enhancement and can result in device performance improvement. Here we report Cd(Se,Te) polycrystalline thin films grown by a chamberless inline atmospheric pressure metal organic chemical vapour deposition technique, with subsequent incorporation in CdTe solar cells. The compositional dependence of the crystal structure and optical properties of Cd(Se,Te) are examined. Selenium graded Cd(Se,Te)/CdTe absorber structure in devices are demonstrated using either a single CdSe layer or CdSe/Cd(Se,Te) bilayer (with or without As doping in the Cd(Se,Te) layer). Cross-sectional TEM/EDS, photoluminescence spectra and secondary ion mass spectroscopy analysis confirmed the formation of a graded Se profile toward the back contact with a diffusion length of ~1.5 μm and revealed back-diffusion of Group V (As) dopants from the CdTe layer into Cd(Se,Te) grains. Due to the strong Se/Te interdiffusion, CdSe in the Se bilayer configuration was unable to form an n-type emitter layer in processed devices. In situ As doping of the Cd(Se,Te) layer benefited the device junction quality with current density reaching 28.3 mA/cm2. The results provide useful insights for the optimisation of Cd(Se,Te)/CdTe solar cells.

AB - Recent developments in CdTe solar cell technology have included the incorporation of ternary alloy Cd(Se,Te) in the devices. CdTe absorber band gap grading due to Se alloying contributes to current density enhancement and can result in device performance improvement. Here we report Cd(Se,Te) polycrystalline thin films grown by a chamberless inline atmospheric pressure metal organic chemical vapour deposition technique, with subsequent incorporation in CdTe solar cells. The compositional dependence of the crystal structure and optical properties of Cd(Se,Te) are examined. Selenium graded Cd(Se,Te)/CdTe absorber structure in devices are demonstrated using either a single CdSe layer or CdSe/Cd(Se,Te) bilayer (with or without As doping in the Cd(Se,Te) layer). Cross-sectional TEM/EDS, photoluminescence spectra and secondary ion mass spectroscopy analysis confirmed the formation of a graded Se profile toward the back contact with a diffusion length of ~1.5 μm and revealed back-diffusion of Group V (As) dopants from the CdTe layer into Cd(Se,Te) grains. Due to the strong Se/Te interdiffusion, CdSe in the Se bilayer configuration was unable to form an n-type emitter layer in processed devices. In situ As doping of the Cd(Se,Te) layer benefited the device junction quality with current density reaching 28.3 mA/cm2. The results provide useful insights for the optimisation of Cd(Se,Te)/CdTe solar cells.

KW - As doping

KW - Cd(Se,Te)

KW - CdSe

KW - CdTe

KW - MOCVD

KW - Photovoltaics

KW - Solar cells

KW - Thin film

UR - http://www.scopus.com/inward/record.url?scp=85112532740&partnerID=8YFLogxK

U2 - 10.1016/j.solmat.2021.111325

DO - 10.1016/j.solmat.2021.111325

M3 - Article

AN - SCOPUS:85112532740

SN - 0927-0248

VL - 231

JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

M1 - Article No. 111325

ER -

Development of Arsenic Doped Cd(Se,Te) Absorbers by MOCVD for Thin Film Solar Cells

Abstract

Bibliographical note

NREL Publication Number

Keywords

UN SDGs

Access to Document

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