How Oxygen Exposure Improves the Back Contact and Performance of Antimony Selenide Solar Cells.

Fleck, Nicole ORCID: 0000-0001-7800-056X, Hutter, Oliver S, Phillips, Laurie J ORCID: 0000-0001-5181-1565, Shiel, Huw, Hobson, Theodore DC ORCID: 0000-0002-0013-360X, Dhanak, Vin R, Veal, Tim D ORCID: 0000-0002-0610-5626, Jäckel, Frank ORCID: 0000-0002-9486-7996, Durose, Ken ORCID: 0000-0003-1183-3211 and Major, Jonathan D ORCID: 0000-0002-5554-1985 (2020) How Oxygen Exposure Improves the Back Contact and Performance of Antimony Selenide Solar Cells. ACS applied materials & interfaces, 12 (47). pp. 52595-52602.

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Abstract

The improvement of antimony selenide solar cells by short-term air exposure is explained using complementary cell and material studies. We demonstrate that exposure to air yields a relative efficiency improvement of n-type Sb2Se3 solar cells of ca. 10% by oxidation of the back surface and a reduction in the back contact barrier height (measured by J-V-T) from 320 to 280 meV. X-ray photoelectron spectroscopy (XPS) measurements of the back surface reveal that during 5 days in air, Sb2O3 content at the sample surface increased by 27%, leaving a more Se-rich Sb2Se3 film along with a 4% increase in elemental Se. Conversely, exposure to 5 days of vacuum resulted in a loss of Se from the Sb2Se3 film, which increased the back contact barrier height to 370 meV. Inclusion of a thermally evaporated thin film of Sb2O3 and Se at the back of the Sb2Se3 absorber achieved a peak solar cell efficiency of 5.87%. These results demonstrate the importance of a Se-rich back surface for high-efficiency devices and the positive effects of an ultrathin antimony oxide layer. This study reveals a possible role of back contact etching in exposing a beneficial back surface and provides a route to increasing device efficiency.

Item Type:	Article
Uncontrolled Keywords:	Sb2Se3, antimony selenide, solar cell, air exposure, back contact barrier, XPS, work function
Depositing User:	Symplectic Admin
Date Deposited:	07 Dec 2020 09:17
Last Modified:	18 Jan 2023 23:19
DOI:	10.1021/acsami.0c14256
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3109490