Time-of-Flight Experiments in Amorphous Chalcogenide Semiconductors

Time-of-Flight Experiments in Amorphous Chalcogenide Semiconductors 

3 TOF Measurements in Selenium-Based Amorphous Multilayer Photoconductors 66 

5 Utilization of Multilayer Structures for the Determination of Transit Time 73 

In recent years, a less familiar technique has been found very useful as a nondestructive method of investigating transport properties of photoreceptors (these are used in nonimpact printers for electronically processed or stored information). The technique is called xerographic TOF (XTOF) and it can be conveniently employed in parallel with the conventional measurements for photoreceptor characterization. In this chapter, we will briefly consider both traditional and xerographic TOF. 

The charge transport in amorphous selenium (a-Se) and Se-based alloys has been the subject of much interest and research inasmuch as it produces charge-carrier drift mobility and the trapping time (or lifetime) usually termed as the range of the carriers, which determine the xerographic performance of a photoreceptor. The nature of charge transport in a-Se alloys has been extensively studied by the TOF transient photoconductivity technique (see, for example. Refs. [1-5] and references cited). This technique currently attracts considerable scientific interest when researchers try to perform such experiments on high-resistivity solids, particularly on commercially important amorphous semiconductors such as a-Si and on a variety of other materials 

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