Field-Enhanced Fluorescence Quenching Methods

Field-enhanced fluorescence quenching techniques have been widely used to study photogeneration during the past two decades (Menzel and Popovic, 1978 Popovic and Menzel, 1979 Popovic, 1982, 1983, 1984 Yokoyama and Mikawa, 1982 Popovic etal., 1985, 1987 Popovic andHor, 1988, 1995 Weiss and Bufbeny, 1988 Niimi and Umeda, 1993 Popovic and Mesbah, 1993 Hor and Popovic, 1994. Fluorescence quenching is not affected by trapping. As with photoacoustical measurements, a fundamental limitation of the technique is 

Bimolecular recombination is the recombination of an independently created electron and hole. Bimolecular recombination depends on the product of the electron and hole concentrations and can become important for high-intensity exposures such as those used in digital xerography (Pai, 1995 Jeyadev and Pai, 1996). For low-mobility materials, bimolecular recombination is usually described by a theory due to Langevin (1903) . The Langevin expression for the recombination coefficient is 

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