Determining thermo-optic coefficients of wide band-gap thin films via thermoelectric effect

Authors

Evan Angelo Quimada Mondarte ⋅ PH National Institute of Physics, University of the Philippines Diliman
Nemesio Mangila ⋅ PH National Institute of Physics, University of the Philippines Diliman
Armando Somintac ⋅ PH National Institute of Physics, University of the Philippines Diliman

Abstract

Index of refraction of a material (n) is significantly affected by heat change. Three thin film samples, TiO₂, AlN and ZnO are subjected to reflectivity measurements at temperatures between 16-70°C operating from 400 to 1100nm with an incident light angle of 90°. From the raw data the thermo- optic coefficients of the three samples (dn/dT) were computed and were found to be -2.9x10^-3 for TiO₂, -1.4x10^-3 for AlN and 9.0x10^-4 for ZnO. Both TiO₂ and AlN thin films have negative values for their thermo-optic coefficients, which are in good agreement to the positive values of their coefficient of thermal expansion. ZnO has a positive thermo-optic coefficient, which could be attributed by the material’s polarisability.

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Issue

2012: Proceedings of the 30th Samahang Pisika ng Pilipinas Physics Congress

Article ID

SPP2012-PB-29

Section

Poster Session PB

Published

2018-11-20

How to Cite

[1]

EAQ Mondarte, N Mangila, and A Somintac, Determining thermo-optic coefficients of wide band-gap thin films via thermoelectric effect, Proceedings of the Samahang Pisika ng Pilipinas 30, SPP2012-PB-29 (2018). URL: https://proceedings.spp-online.org/article/view/SPP2012-PB-29.