Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-27T12:20:28.448Z Has data issue: false hasContentIssue false
  • English
  • Français

Nano-scale compositional analysis of surfaces and interfaces in earth-abundant kesterite solar cells

Published online by Cambridge University Press:  02 November 2016

Kasra Sardashti ,
Dennis Paul ,
Chuck Hitzman ,
John Hammond ,
Richard Haight  and
Andrew C. Kummel
Kasra Sardashti
Affiliation:
Materials Science Program, University of California–San Diego, La Jolla, CA 92093, USA; and Department of Chemistry and Biochemistry, University of California–San Diego, La Jolla, CA 92093, USA
Dennis Paul
Affiliation:
Physical Electronic, Inc., Chanhassen, MN 55317, USA
Chuck Hitzman
Affiliation:
Stanford Nano Shared Facilities, Stanford, CA 94305, USA
John Hammond
Affiliation:
Physical Electronic, Inc., Chanhassen, MN 55317, USA
Richard Haight
Affiliation:
IBM T J Watson Research Center, Yorktown Heights, NY 10598, USA
Andrew C. Kummel*
Affiliation:
Department of Chemistry and Biochemistry, University of California–San Diego, La Jolla, CA 92093, USA
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) absorbers are considered promising alternatives to commercial thin film technologies including CdTe and Cu(In,Ga)Se2 (CIGSe) owing to the earth abundance and non-toxicity of their constituents. However, to be competitive with the existing technologies, the photovoltaic performance of CZTSSe solar cells needs to be improved beyond the current record conversion efficiency of 12.6%. In this study, nanoscale elemental mapping using Auger nanoprobe microscopy (NanoAuger) and nano secondary ion mass spectrometry (NanoSIMS) are used to provide a clear picture of the compositional variations between the grains and grain boundaries in Cu2ZnSn(S,Se)4 kesterite thin films. NanoAuger measurements revealed that the top surfaces of the grains are coated with a Zn-rich (Zn,Sn)Ox layer. While thick oxide layers were observed at the grain boundaries, their chemical compositions were found to be closer to SnOx . NanoSIMS elemental maps confirmed the presence of excess oxygen deeper within the grain boundary grooves, as a result of air annealing of the CZTSSe films.

Keywords

Alalloycasting
Type
Invited Feature Paper
Information
Journal of Materials Research , Volume 31 , Issue 22 , 28 November 2016 , pp. 3473 - 3481
Check for updates
Copyright
Copyright © Materials Research Society 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Candelise, C., Winskel, M., and Gross, R.: Implications for CdTe and CIGS technologies production costs of indium and tellurium scarcity. Prog. Photovoltaics 20(6), 816 (2012).CrossRefGoogle Scholar
Mitzi, D.B., Gunawan, O., Todorov, T.K., and Barkhouse, D.A.R.: Prospects and performance limitations for Cu–Zn–Sn–S–Se photovoltaic technology. Philos. Trans. R. Soc., A 371, 20110432 (2013).CrossRefGoogle ScholarPubMed
Liu, X.L., Feng, Y., Cui, H.T., Liu, F.Y., Hao, X.J., Conibeer, G., Mitzi, D.B., and Green, M.: The current status and future prospects of kesterite solar cells: A brief review. Prog. Photovoltaics 24(6), 879 (2016).CrossRefGoogle Scholar
Wang, W., Winkler, M.T., Gunawan, O., Gokmen, T., Todorov, T.K., Zhu, Y., and Mitzi, D.B.: Device characteristics of CZTSSe thin-film solar cells with 12.6% efficiency. Adv. Energy Mater. 4(7), 1301465 (2014).CrossRefGoogle Scholar
Chagarov, E., Sardashti, K., Kummel, A.C., Lee, Y.S., Haight, R., and Gershon, T.S.: Ag2ZnSn(S,Se)(4): A highly promising absorber for thin film photovoltaics. J. Chem. Phys. 144(10), 104704 (2016).CrossRefGoogle Scholar
Kattan, N.A., Griffiths, I.J., Cherns, D., and Fermin, D.J.: Observation of antisite domain boundaries in Cu2ZnSnS4 by atomic-resolution transmission electron microscopy. Nanoscale 8, 14369 (2016).CrossRefGoogle ScholarPubMed
Gokmen, T., Gunawan, O., Todorov, T.K., and Mitzi, D.B.: Band tailing and efficiency limitation in kesterite solar cells. Appl. Phys. Lett. 103(10), 103506 (2013).CrossRefGoogle Scholar
Scragg, J.J., Dale, P.J., Colombara, D., and Peter, L.M.: Thermodynamic aspects of the synthesis of thin-film materials for solar cells. ChemPhysChem 13(12), 3035 (2012).CrossRefGoogle ScholarPubMed
Jiang, C.S., Contreras, M.A., Repins, I., Moutinho, H.R., Yan, Y., Romero, M.J., Mansfield, L.M., Noufi, R., and Al-Jassim, M.M.: How grain boundaries in Cu(In,Ga)Se-2 thin films are charged: Revisit. Appl. Phys. Lett. 101(3), 033903 (2012).CrossRefGoogle Scholar
Jiang, C.S., Repins, I.L., Mansfield, L.M., Contreras, M.A., Moutinho, H.R., Ramanathan, K., Noufi, R., and Al-Jassim, M.M.: Electrical conduction channel along the grain boundaries of Cu(In,Ga)Se-2 thin films. Appl. Phys. Lett. 102(25), 253905 (2013).CrossRefGoogle Scholar
Sardashti, K., Haight, R., Anderson, R., Contreras, M., Fruhberger, B., and Kummel, A.C.: Grazing incidence cross-sectioning of thin-film solar cells via cryogenic focused ion beam: A case study on CIGSe. ACS Appl. Mater. Interfaces. 8(24), 14994 (2016).CrossRefGoogle Scholar
Abou-Ras, D., Schmidt, S.S., Caballero, R., Unold, T., Schock, H.W., Koch, C.T., Schaffer, B., Schaffer, M., Choi, P.P., and Cojocaru-Miredin, O.: Confined and chemically flexible grain boundaries in polycrystalline compound semiconductors. Adv. Energy Mater. 2(8), 992 (2012).CrossRefGoogle Scholar
Erkan, M.E., Chawla, V., Repins, I., and Scarpulla, M.A.: Interplay between surface preparation and device performance in CZTSSe solar cells: Effects of KCN and NH4OH etching. Sol. Energy Mater. Sol. Cells 136, 78 (2015).CrossRefGoogle Scholar
Jiang, C.S., Repins, I.L., Beall, C., Moutinho, H.R., Ramanathan, K., and Al-Jassim, M.M.: Investigation of micro-electrical properties of Cu2ZnSnSe4 thin films using scanning probe microscopy. Sol. Energy Mater. Sol. Cells 132, 342 (2015).CrossRefGoogle Scholar
Xin, H., Vorpahl, S.M., Collord, A.D., Braly, I.L., Uhl, A.R., Krueger, B.W., Ginger, D.S., and Hillhouse, H.W.: Lithium-doping inverts the nanoscale electric field at the grain boundaries in Cu2ZnSn(S,Se)(4) and increases photovoltaic efficiency. Phys. Chem. Chem. Phys. 17(37), 23859 (2015).CrossRefGoogle Scholar
Gershon, T., Shin, B., Bojarczuk, N., Hopstaken, M., Mitzi, D.B., and Guha, S.: The role of sodium as a surfactant and suppressor of non-radiative recombination at internal surfaces in Cu2ZnSnS4 . Adv. Energy Mater. 5(2), 1400849 (2015).CrossRefGoogle Scholar
Kim, J.H., Choi, S.Y., Choi, M., Gershon, T., Lee, Y.S., Wang, W., Shin, B., and Chung, S.Y.: Atomic-scale observation of oxygen substitution and its correlation with hole-transport barriers in Cu2ZnSnSe4 thin-film solar cells. Adv. Energy Mater. 6(6), 1501902 (2016).CrossRefGoogle Scholar
Sardashti, K., Haight, R., Gokmen, T., Wang, W., Chang, L.Y., Mitzi, D.B., and Kummel, A.C.: Impact of nanoscale elemental distribution in high-performance kesterite solar cells. Adv. Energy Mater. 5(10), 1402180 (2015).CrossRefGoogle Scholar
Haight, R., Shao, X.Y., Wang, W., and Mitzi, D.B.: Electronic and elemental properties of the Cu2ZnSn(S,Se)(4) surface and grain boundaries. Appl. Phys. Lett. 104(3), 033902 (2014).CrossRefGoogle Scholar
Hiepko, K., Bastek, J., Schlesiger, R., Schmitz, G., Wuerz, R., and Stolwijk, N.A.: Diffusion and incorporation of Cd in solar-grade Cu(In,Ga)Se-2 layers. Appl. Phys. Lett. 99(23), 234101 (2011).CrossRefGoogle Scholar
Nakada, T. and Kunioka, A.: Direct evidence of Cd diffusion into Cu(In,Ga)Se-2 thin films during chemical-bath deposition process of CdS films. Appl. Phys. Lett. 74(17), 2444 (1999).CrossRefGoogle Scholar
Barkhouse, D.A.R., Gunawan, O., Gokmen, T., Todorov, T.K., and Mitzi, D.B.: Device characteristics of a 10.1% hydrazine-processed Cu2ZnSn(Se,S)4 solar cell. Prog. Photovoltaics 20(1), 6 (2012).CrossRefGoogle Scholar
Todorov, T.K., Reuter, K.B., and Mitzi, D.B.: High-efficiency solar cell with earth-abundant liquid-processed absorber. Adv. Mater. 22(20), E156 (2010).CrossRefGoogle ScholarPubMed
Todorov, T.K., Tang, J., Bag, S., Gunawan, O., Gokmen, T., Zhu, Y., and Mitzi, D.B.: Beyond 11% efficiency: Characteristics of state-of-the-art Cu2ZnSn(S,Se)(4) solar cells. Adv. Energy Mater. 3(1), 34 (2013).CrossRefGoogle Scholar
Jablonski, A. and Powell, C.J.: Information depth and the mean escape depth in Auger electron spectroscopy and X-ray photoelectron spectroscopy. J. Vac. Sci. Technol., A 21(1), 274 (2003).CrossRefGoogle Scholar
Jablonski, A. and Powell, C.J.: Practical expressions for the mean escape depth, the information depth, and the effective attenuation length in Auger-electron spectroscopy and x-ray photoelectron spectroscopy. J. Vac. Sci. Technol., A 27(2), 253 (2009).CrossRefGoogle Scholar
Lynn, L.C. and Opila, R.L.: Chemical-shifts in the MNN Auger-spectra of Cd, in, Sn, Sb and Te. Surf. Interface Anal. 15(2), 180 (1990).CrossRefGoogle Scholar
Milosev, I., Mikic, T.K., and Gaberscek, M.: The effect of Cu-rich sub-layer on the increased corrosion resistance of Cu–xZn alloys in chloride containing borate buffer. Electrochim. Acta 52(2), 415 (2006).CrossRefGoogle Scholar
Bar, M., Schubert, B.A., Marsen, B., Krause, S., Pookpanratana, S., Unold, T., Weinhardt, L., Heske, C., and Schock, H.W.: Native oxidation and Cu-poor surface structure of thin film Cu2ZnSnS4 solar cell absorbers. Appl. Phys. Lett. 99(11), 112103 (2011).CrossRefGoogle Scholar