Kinetics and chemical analysis of photoinduced interdiffusion in nanolayered $Se/As_2S_3$ films

Autor: Adarsh, KV, Naik, Ramakanta, Sangunni, KS, Kokenyesi, S, Jain, H, Miller, Alfred C
Jazyk: angličtina
Rok vydání: 2008
Předmět:
Zdroj: IndraStra Global.
ISSN: 2381-3652
Popis: We have studied the kinetics of photoinduced effects in nanolayered $Se/As_2S_3$ film by in situ optical absorption measurements, which reveal that photodarkening in these films is followed by photoinduced diffusion. An increase in disorder during photodarkening and its. subsequent decrease during photoinduced diffusion were also observed. The observation of photodarkening of Se at room temperature when confined between $As_2S_3$ layers suggests that the glass transition temperature of Se shifts to higher energy. The analysis shows that the atoms which take part in photodarkening play a vital role in photoinduced diffusion. The x-ray photoelectron spectroscopy measurements show the atomic movements during photoinduced diffusion. It also shows that some of the As-S bonds are converted into As-Se bonds. Since it is energetically difficult to break an As-S bond to form an As-Se bond, we assume that the new bond formations are taking place by the bond rearrangement mechanism.
Databáze: OpenAIRE