Application of photon counting techniques to measurement of the risetime of chromium (III) phosphorescence in the near infrared

Publisher Website
Google Scholar
Abstract
An extremely sensitive system for luminescence decay lifetime measurements based on multichannel delayed coincidence photon counting is described. The stop channel photomultiplier is an RCA C31034 gallium arsenide photocathode type, resulting an in system capable of measurements on emissions with lifetimes in the range nanoseconds to tens of microseconds, and spanning the wavelength range 300 nm to at least 900 nm. The system has been used to seek a risetime of phosphorescence from chromium (III) complexes in room temperature and cooled solutions. No risetime could be observed. An upper limit of 10 nsec can therefore be placed on the risetime for the compounds studied except for [Cr(en)3]3+, where an upper limit of 1 nsec has been established.