Characterization of thin coatings based on ZnO for photonic applications

R. PARRA; ALVIRA, F. C.; G. SUAREZ; M. R. TEJERINA

JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS

NATL INST OPTOELECTRONICS

Año: 2019 vol. 13 p. 535 - 538

1454-4164

We present a comparison between zinc oxide films made by sol-gel dip-coating and spray-pyrolysis to be employed in opto-electronic applications. Grain size, shape, roughness, thickness, band gap, composition, crystalline orientation, electrical resistivity, and optical guided modes were evaluated by AFM, SEM, EDS, optical transmittance, electrical resistance, and end-fire coupling method, respectively. From these results, it was determined that dip-coated film is thinner (with a thickness of about 130 nm) than the spray-pyrolysis one (of about 500 nm), whereas the former showed lower roughness and higher electrical resistivity. Furthermore, a 532 nm continuous laser was coupled across the sprayed film because of its greater thickness. We conclude that the studied techniques can be complementarily implemented to obtain high-performance coatings for photonic applications, combining the lower roughness of dip coating and the wider thickness of spray-pyrolysis films.