Photoluminescence studies on lead selenide thin films from thermal evaporation  

By S. Prabahar N. Suryanarayanan,  V. Balasubramanian,  S. srikanth,  D. Kathirvel 

ABSTRACT

Thin films of PbSe are prepared by vacuum deposition technique on to well cleaned glass substrates. The film thicknesses are measured by quartz crystal monitor method. There is a blue shift in the PL Spectrum of PbSe thin films of different thicknesses were observed. A strong emission peak is observed at 606 nm. The excitation wavelength was 441 nm. This effect may be related to the quantum effects.  PL emission intensity increases with thickness. The emission peak occurs at a higher wavelength than that of the absorption peaks.  In fact   the peak emission wavelength is invariably shifted towards red end of the spectrum compared to the peak of the absorption spectrum.  This phenomenon is known as the Stokes shift. 

Keywords: PbSe, Vacuum deposition, Photoluminescence Studies, Substrate, Thin films.

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