A1 Journal article (refereed)
Structural and Optical Characterization of ZnS Ultrathin Films Prepared by Low-Temperature ALD from Diethylzinc and 1.5-Pentanedithiol after Various Annealing Treatments (2019)

Włodarski, M., Chodorow, U., Jóźwiak, S., Putkonen, M., Durejko, T., Sajavaara, T., & Norek, M. (2019). Structural and Optical Characterization of ZnS Ultrathin Films Prepared by Low-Temperature ALD from Diethylzinc and 1.5-Pentanedithiol after Various Annealing Treatments. Materials, 12(19), Article 3212. https://doi.org/10.3390/ma12193212

JYU authors or editors

Publication details

All authors or editors: Włodarski, M.; Chodorow, U.; Jóźwiak, S.; Putkonen, M.; Durejko, T.; Sajavaara, T.; Norek, M.

Journal or series: Materials

eISSN: 1996-1944

Publication year: 2019

Volume: 12

Issue number: 19

Article number: 3212

Publisher: MDPI AG

Publication country: Switzerland

Publication language: English

DOI: https://doi.org/10.3390/ma12193212

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/65824

Additional information: This article belongs to the Special Issue Novel Thin Films: Electrical and Optical Properties

Abstract

The structural and optical evolution of the ZnS thin films prepared by atomic layer deposition (ALD) from the diethylzinc (DEZ) and 1,5-pentanedithiol (PDT) as zinc and sulfur precursors was studied. A deposited ZnS layer (of about 60 nm) is amorphous, with a significant S excess. After annealing, the stoichiometry improved for annealing temperatures ≥400 °C and annealing time ≥2 h, and 1:1 stoichiometry was obtained when annealed at 500 °C for 4 h. ZnS crystallized into small crystallites (1–7 nm) with cubic sphalerite structure, which remained stable under the applied annealing conditions. The size of the crystallites (D) tended to decrease with annealing temperature, in agreement with the EDS data (decreased content of both S and Zn with annealing temperature); the D for samples annealed at 600 °C (for the time ≤2 h) was always the smallest. Both reflectivity and ellipsometric spectra showed characteristics typical for quantum confinement (distinct dips/peaks in UV spectral region). It can thus be concluded that the amorphous ZnS layer obtained at a relatively low temperature (150 °C) from organic S precursor transformed into the layers built of small ZnS nanocrystals of cubic structure after annealing at a temperature range of 300–600 °C under Ar atmosphere.

Keywords: thin films; atomic layer deposition

Free keywords: atomic layer deposition (ALD); ZnS thin films; annealing; optical properties

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2019

JUFO rating: 1