Deferred Isothermal Luminescence in organic glasses irradiated at 4·2 and 77 K: Tunnelling and thermal detrapping

Abstract

At 4·2 K the isothermal luminescence (ITL) decay of both methylcyclohexane (MCH) and 3-methylpentane (3-MP) glasses containing biphenyl can be expressed by a reciprocal time law which seems to be generally observed when electron tunnelling occurs. At 77 K, the same law applies only to the ITL decay of MCH glass, while that of 3-MP glass follow a reciprocal time-square law corresponding to a thermal electron detrapping mechanism. Distances of the order of 60–100 Å between cation and trapped electron in MCH are calculated from a formulation based on electron tunnelling.