Thermal annealing effect on physical properties of DNA–CTMA thin films

•Thermal annealing of DNA–CTMA thin films.•Ellipsometry, FT-IR spectroscopy, dielectric spectroscopy characterize material.•Thermally induced irreversible changes of microstructure.

DNA–CTMA is a material of increasing interest in the domain of organic electronics and photonics. However, its physical properties are not sufficiently understood. In this work DNA–CTMA thin films were subjected to thermal annealing. Annealing courses was monitored in situ by spectroscopic ellipsometry, infrared spectroscopy and dielectric spectroscopy. The results suggest existence of an irreversible structural transition, occurring at a temperature adjacent to 150 °C.