PHENOMENON OF BISTABILITY IN LUMINESCENCE

A new nonlinear feature of semiconductors is presented: bistability in luminescence of thin (<15 mu m) CdS:Cu films. The well known bistable behaviour in transmission, reflection and photo-current was investiga ted with the 514.5 nm argon ion laser line optical excitation of the s ample. Measurements of the reflection showed only very poor contrasted (7%) bistable loops. When the cut-off filters which are transparent i n the red region of the spectrum were put in the reflected beam, very well contrasted (>70%) bistable loops were observed. It is presumed th at the bistable snitch of the infrared luminescent light was observed.