Electrical and optical phototransformation properties in As doped Se thin films

Selenium doped with arsenic thin films prepared by thermal evaporation were exposed to white light in air. The structure of thin films gradually chang ed from amorphous to polycrystalline as the time of exposure and film tempe rature increased. The grain size increases up to 27.69 nm when the As doped Se thin film was exposed to light for 1 h. The electrical resistivity beha viour as a function of temperature and exposure time was detected for films deposited on glass and mica substrates. The activation energies were calcu lated in darkness and during illumination for deposited materials. The refr active index (n) and absorption coefficient (alpha) were determined before and after phototransformation. (C) 1999 Elsevier Science S.A. All rights re served.