Model experiments on growth modes and interface electronics of CuInS2: Ultrathin epitaxial films on GaAs(100) substrates. Issue 9 (19th July 2014)

• Record Type: Journal Article
• Authors: Calvet, Wolfram; Lewerenz, Hans‐Joachim; Pettenkofer, Christian
• Is Part Of: Physica status solidi. Volume 211:Issue 9(2014:Sep.)
• Page Start: 1981
• Page End: 1990
• Publication Date: 2014-07-19
• Subjects: Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201330429
• Languages: English
• ISSNs: 1862-6300

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pssa201330429-sec-0001" sec-type="section"> <p>The heterojunction formation between GaAs(100) and CuInS₂ is investigated using ultraviolet photoelectron spectroscopy (UPS), X‐ray photoelectron spectroscopy (XPS), and low energy electron diffraction (LEED). Thin layers of CuInS₂ films were deposited in a step‐by‐step process on wet chemically pre‐treated GaAs(100) surfaces by molecular beam epitaxy (MBE) with a total upper thickness limit of the films of 60 nm. The film growth starts from a sulfur‐rich GaAs(100) surface. XPS core level analysis of the substrate and film reveals initially a transitory growth regime with the formation of a Ga containing chalcopyrite phase. With increasing film thickness, a change in stoichiometry from Cu‐poor to Cu‐rich composition is observed. The evaluation of the LEED data shows the occurrence of a recrystallization process where the film orientation follows that of the substrate with the epitaxial relation GaAs{100}||CuInS₂{001}. On the completed junction with a CuInS₂ film thickness of 60 nm, the band discontinuities of the GaAs(100)/CuInS₂ structure measured with XPS and UPS were determined as Δ<italic>E</italic>_V<italic> = </italic>0.1 ± 0.1 eV and Δ<italic>E</italic>_C<italic> = </italic>0.0 ± 0.1 eV, thus showing a type II band alignment.</p> </sec> </abstract>