Poly photocurrent transient measurements

The major advantages of the HTOF technique are that it is not subject to trapping constraints nor the restrictions concerning the absorption depth of conventional photocurrent transient measurements. The principal limitation is that it is limited to photorefractive materials. Malliaras et al. (1995) used the HTOF method to measure mobilities of ternary mixtures of poly(N-vinylcarbazole), 2.4.7-trinitro-9-fluorenone, and 4-(hexyloxy)nitrobenzene. Results obtained by the HTOF method were in good agreement with those obtained by conventional photocurrent transient measurements. 

Borsenberger et al. (1993a) measured hole mobilities of TAPC doped poly(styrene)s with different dipole moments poly(styrene) (PS-1), poly(4-f-butylstyrene) (PS-2), and poly(4-chlorostyrene) (PS-3). The dipole moments of PS-1, PS-2, and PS-3 are f 1.0, and 1.7 Debye, respectively. Figure 32 shows a series of room temperature photocurrent transients for 40% TAPC doped PS. ... 

Borsenberger et al. (1995a) measured hole mobilities of TTA doped polymers with polymers with different dipole moments poly(styrene) (PS-1), poly(4-f-butylstyrene) (PS-2), poly(4-chlorostyrene) (PS-3), and bisphenol-A polycaibonate (PC). The dipole moments of PS-1 and PS-2 are near zero. For PC and PS-3, the values are 1.0 and 1.7 Debye. The dipole moment of TTA is 0.8 Debye. Figure 55 shows a series of photocurrent transients at different temperatures for 30% TTA doped PS-1 at 6.4 x 105 V/cm. W increases with decreasing temperature. For fields between 104 and a few multiples of 1CP v/cm, W increases with increasing field. Values of W were between 0.25 and 0.62. In all cases, W increases with decreasing TTA concentratioa Low-temperature transitions from nondispersive to dispersive transport, where the transients no longer show plateaus, were observed only at low concentrations. 

Abkowitz et al. (1987, 1990a), Stolka and Abkowitz (1987), Stolka et al. (1987), and Abkowitz and Stolka (1988) measured hole mobilities of PMPS, poly(methylcyclohexylsilylene), poly(methyl-M-propylsilylene), poly(methyl-p-methoxyphenylsilylene), and poly(ethylphenylsilylene). The photocurrent transients were nondispersive over a wide range of temperatures. At room temperature, the mobility of PMPS was 1.0 x 10-4 Cm2/Vs at 1.0 x 105 V/cm, varying with field as logjU j8E 2 xi,e results were in good agreement with... 

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