On the Optimum Efficiency of Cathodoluminescence of Inorganic Phosphors

Abstract

The maximum possible efficiency of a phosphor excited by an electron beam depends primarily on the mean excitation energy required to create, by collision, a free electron‐hole pair or a free carrier‐ionized activator pair or an excited but nonionized activator. This energy is expressed as a multiple (factor α) of the band gap energy, . Values of α measured for various phosphors scatter over a wide range depending on host material and activator and, in many cases, strongly deviating from observed in free‐carrier‐collection experiments in semiconductors.