Hole drift mobility, calculation

Figure 13 Positive hole drift mobility in liquid xenon as a function of temperature. Solid line calculated according to Equation 36. (Redrawn from the data of Hilt, O. and Schmidt, W.F., /. Phys. Condens. Matter, 6, L735, 1994.)...

The assignment of ti, t2, and t- (see inflection points in Fig. 4.17) to transit times in the top, middle, and bottom layers is supported by the fact that the drift mobility of charge carriers for the three layers were calculated to be similar to the corresponding single layers. The general features of current waveforms described earlier are common to both hole and electron response. 

For positive lit electrodes one can register the drift of holes, and for negative ones- the drift of the electrons. The photosensitizer (for example Se) may be used for carrier photoinjection in the polymer materials if the polymer has poor photosensitivity itself. The analysis of the electrical pulse shape permits direct measurement of the effective drift mobility and photogeneration efficiency. The transit time is defined when the carriers reach the opposite electrode and the photocurrent becomes zero. The condition RC < tlr and tr > t,r should be obeyed for correct transit time measurement. Here R - the load resistance, Tr -dielectric relaxation time. Usually ttras 0, 1-100 ms, RC < 0.1 ms and rr > 1 s. Effective drift mobility may be calculated from Eq. (4). The quantum yield (photogenerated charge carriers per absorbed photon) may be obtained from the photocurrent pulse shape analysis. 

Fig. 7.9. Temperature dependence of the acousto-electric voltage, and drift mobility of (a) electrons and (b) holes obtained by the SAW technique, llie solid lines are calculated for trapping in an exponential band tail of slope 7J. or 7 (Takada and Fritzsche 1987).

Fig. tr.1-39 Diamond. Hole mobility vs. temperature. Open circles, drift mobility data from [1.31] filled circles and filled triangles. Hall mobility data from [1.29, 30] and [1.32], respectively. Solid and dashed curves calculated drift and Hall mobilities, respectively [1.33]... 

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