High Temperature Photochemical Hole Burning of Tetrasodium 5,10,15,20-tetra(4-sulfonatophenyl)porphin in Polyvinylalcohol

Abstract
Persistent spectral holes were burned in a film composed of tetrasodium 5,10,15,20-tetra(4-sulfonatophenyl)porphin and polyvinylalcohol at 20 K–80 K. This is the first observation of a photochemical hole burned above liquid nitrogen temperature. The hole width increased with temperature according to power-law dependence from 20 K to 80 K.