Optimization of Electrochemically Deposited Highly Doped ZnO Bilayers on Ga-Rich Chalcopyrite Selenide for Cost-Effective Photovoltaic Device Technology

Dimitra N. Papadimitriou, Georgios Roupakas, Georgios G. Roumeliotis, Patrick Vogt and Tristan Köhler
Additional contact information
Dimitra N. Papadimitriou: National Technical University of Athens, Heroon Polytechniou 9, GR-15780 Athens, Greece
Georgios Roupakas: National Technical University of Athens, Heroon Polytechniou 9, GR-15780 Athens, Greece
Georgios G. Roumeliotis: National Technical University of Athens, Heroon Polytechniou 9, GR-15780 Athens, Greece
Patrick Vogt: Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstr. 36, DE-10623 Berlin, Germany
Tristan Köhler: Helmholtz Zentrum Berlin für Materialien und Energie, Institut für Heterogene Materialsysteme, Hahn-Meitner-Platz 1, DE-14109 Berlin, Germany

Energies, 2016, vol. 9, issue 11, 1-28

Abstract: High quality polycrystalline bilayers of aluminium doped ZnO (Al:ZnO) were successively electrodeposited in the form of columnar structures preferentially oriented along the ( 10 1 ¯ 1 ) crystallographic direction from aqueous solution of zinc nitrate (Zn(NO 3 ) 2 ) at negative electrochemical potential of E C = (?0.8)–(?1.2) V and moderate temperature of 80 °C on gallium rich (30% Ga) chalcopyrite selenide Cu(In,Ga)Se 2 (CIGS) with chemically deposited ZnSe buffer (ZnSe/Cu(In,Ga)Se 2 /Mo/glass). The aluminium doped ZnO layer properties have initially been probed by deposition of Al:ZnO/i-ZnO bilayers directly on Mo/glass substrates. The band-gap energy of the Al:ZnO/i-ZnO reference layers was found to vary from 3.2 to 3.7 eV by varying the AlCl 3 solute dopant concentration from 1 to 20 mM. The electrical resistivity of indium-pellet contacted highly doped Al:ZnO sheet of In/Al:ZnO/i-ZnO/Mo/glass reference samples was of the order ? ~10 ?5 ?·cm; the respective carrier concentration of the order 10 22 cm ?3 is commensurate with that of sputtered Al:ZnO layers. For crystal quality optimization of the bilayers by maintenance of the volatile selenium content of the chalcopyrite, they were subjected to 2-step annealing under successive temperature raise and N 2 flux regulation. The hydrostatic compressive strain due to Al 3+ incorporation in the ZnO lattice of bilayers processed successively with 5 and 12 mM AlCl 3 dopant was ? h = ?0.046 and the respective stress ? h = ?20 GPa. The surface reflectivity of maximum 5% over the scanned region of 180–900 nm and the (optical) band gap of E g = 3.67 eV were indicative of the high optical quality of the electrochemically deposited (ECD) Al:ZnO bilayers.

Keywords: CIGS photovoltaics; oriented Al:ZnO bilayers; ECD process optimization; annealing T-threshold; X-ray diffraction; scanning electron microscopy; transmittance/reflectance spectroscopy; current-voltage measurements; van der Pauw measurement techniques (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2016
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/9/11/951/pdf (application/pdf)
https://www.mdpi.com/1996-1073/9/11/951/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:9:y:2016:i:11:p:951-:d:82862

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().