Laser-induced changes in optical properties of amorphous films of the system Ge-Se

• Дата: 2024
• Автори: Рубіш, В. М., Поп, М. М., Петров, В. В., Макар, Л. І., Крючин, А. А., Ясінко, Т. І., Рубіш, В. В., Микайло, О. А., Кайнц, Д. І., Костюкевич, С. О.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Інститут проблем реєстрації інформації НАН України 2024
• Теми: amorphous films; optical characteristics and parameters; photo-induced effects
• Онлайн доступ: http://drsp.ipri.kiev.ua/article/view/316668
• Назва журналу: Data Recording, Storage & Processing

The influence of laser radiation with λ = 530 and 650 nm on the transmission spectra of amorphous GeSex films was studied. The calculated values of pseudo forbidden gap Eg and refractive index n of films. Two types of photo-induced effects in the films have been identified — photobrightening (GeSe5, GeSe3, GeSe2) and photodarkening (GeSe15, Ge2Se3). At photodarkening of the films their Eg decreases and n increases also. It was established that the level of changes in the optical parameters of GeSe5 and GeSe15 films upon their laser irradiation is much higher than that of films of other compositions (GeSe8, GeSe4, GeSe3, GeSe2, Ge2Se3). For the GeSe8 film, oscillations were detected in the dependences of Eg and n on their exposure time (λ = 530 nm). At short exposure times (up to 1 min.), photodarkening of films takes place. As the exposure time increases, the GeSe8 film brightens. However, the level of changes in the optical parameters of the film of the specified composition is very low. When the GeSe8 film is exposed to red laser radiation, the transmission spectra shift to the short-wavelength part of the spectrum (brightening of film). For films of other compositions, the spectra shift weakly into the long-wavelength region. For GeSe4 and GeSe3 films, oscillations (photodarkening — photobrightening) were detected on the dependences of Eg and n on the exposure time. Some differences in the results of studies of the films when they are irradiated with green and red lasers are associated with a photoplastic effect, which appears in them when illuminated by light from the region of the edge of its own absorption.