Comparative study of perhydropolysilazane protective films

ABSTRACT

Silicon dioxide thin films are a promising alternative to protective glass in solar cells. In this work, one-layer and four-layer thin films of a perhydropolysilazane (PHPS) were spin-coated from solution in dibutyl ether and cured by exposure to moderate temperatures or ultraviolet (UV) light to obtain glassy SiO_x layers. Optical and morphological properties as well as their long-term stability were studied using XPS, FTIR, UV-Vis spectroscopy, and SEM microscopy with EDX analysis. The results showed that the process of converting PHPS layers to SiO_x continues after the completion of the curing procedure for both methods. However, the composition of the thermally cured films is similar to silicon oxide, while the UV-cured samples demonstrate a composition similar to silicon dioxide due to differences in the reactions occurring during the curing process. The prolonged transformation process opens up possibilities for creating self-improving protective coatings based on PHPS.

GRAPHICAL ABSTRACT

KEYWORDS:

• PHPS
• polysilazane
• pre-ceramic
• polymer
• thermal
• UV
• curing
• barrier
• protective
• coating

Acknowledgements

The authors thanks Kaia Tõnsuaadu for her help with the ATR-FTIR measurements.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the European Union through the European Regional Development Fund (ERDF) project “Center of Excellence” under [grant number TK141]; by ERDF project Centre of Technologies and Investigations of Nanomaterials NAMUR+ under [grant number 2014-2020.4.01.16-0123]; NAMUR+ core facility funded by the Estonian Research Council under [grant number TT13] and by the Estonian Research Council under [grant number PRG1023]. This work has been partially supported by ASTRA ‘TUT Institutional Development Programme for 2016-2022 ‘Graduate School of Functional Materials and Technologies’ under [grant number 2014-2020.4.01.16-0032]’.