Generation of Electrons and Holes in Anthracene by Ruby Laser Light

The number of carriers generated in an anthracene crystal by a pulse of light from a Q-spoiled ruby laser has been investigated. The number observed far exceeds the number expected on the basis of existing theoretical predictions, varies approximately as the intensity of the laser light cubed and increases exponentially with increasing temperature as e −To/T where T 0=2 × 103 °K. The carriers are generated uniformly throughout the volume of the crystal. A neodymium laser pulse of the same energy density produced no detectable signal so it is concluded that the carriers are not produced by the electric field associated with the light pulse.