The solid-state photoluminescent quantum yield of triboluminescent materials

Ground rules defining design of triboluminescent (TL) materials are current ly missing, in part since the triboluminescent efficiency is the product of the efficiency of excited-state formation and the efficiency of radiative relaxation from these excited-states. In order to de-couple these two proce sses, we have measured, for the first time, the solid-state photoluminescen t quantum yield of various triboluminescent materials. The measurements hig hlighted: (i) some triboluminescent materials possess near-optimised radiat ive yields; (ii) structurally similar triboluminescent compounds can exhibi t widely varying yields and (iii) some triboluminescent materials, which ap pear to the eye as reasonably efficient, possess low radiative yields, allo wing possible triboluminescent enhancement. (C) 2001 Published by Elsevier Science B.V.