Properties of SnO2:F thin films prepared by using HF or NH4F after exposure to atmosphere

Year 2017, Volume: 1 Issue: 3, 120 - 128, 13.12.2017

Shadia Ikhmayies

https://doi.org/10.30521/jes.360535

Cited By: 3

Abstract

Nanocrystalline fluorine
doped tin oxide (SnO₂:F) thin films were produced by the spray
pyrolysis technique (SP) on glass substrates at a substrate temperature T_s
= 450 °C. The hydrated stannous chloride (SnCl₂.2H₂O) was
used as a precursor and ammonium fluoride (NH₄F) was used as the
doping compound for one set of films, and hydrofluoric acid (HF) was used as
the doping compound to produce another set of films. After exposure to
atmosphere for about one month, a comparison between the compositional,
morphological and optical properties of the films obtained by using the two
doping compounds was performed by using scanning electron microscope (SEM)
observations, X-ray energy dispersive spectroscopy (EDS) and transmittance
measurements. Both sets of films are found to be oxygen rich, but the films
prepared by using NH₄F have higher oxygen content. SEM images showed
that the films prepared by using HF have larger grain size, and EDS analysis
showed that these films have higher fluorine to oxygen ratio. In addition, the
films prepared by using HF have lower transmittance and higher direct optical
bandgap energy. These results are interesting for the use of SnO₂:F  as a fore contact in CdS/CdTe solar cells.

Keywords

Transparent conducting oxides, Spray pyrolysis, Doping, CdS/CdTe solar cells

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