Time Resolution of Carrier Photogeneration Controlled by Geminate Recombination

With use of a delayed-field technique, the unusual observation has been made that the quantum efficiency in poly(N-vinyl carbazole), for a given field, is the same whether the pulse photoexcitation occurs with the field applied or delayed up to many seconds. A possible explanation is that the geminate recombination rate is sufficiently slow that it allows the photogeneration process to be time resolved.