The time-dependent behavior of the photocurrent is known as transient photoconductivity. As explained in Chapter 2, transient forms are generally recorded on an oscilloscope and, more recently but not frequently, they are recorded in digitized form with the help of a computer. Commonly observed forms of relaxation (transient) curves are shown in Fig. 3.1. Even in correctly performed experiments, several forms of rise and decay curves are reported. Photoresponse may vary widely with time, and, depending upon the presence of defect states (traps) and their distribution, the observed curve may also deviate frequently from a simple exponential. In principle, photoconductivity may also become one of the powerful techniques for studying optically active traps since the transient curves contain a wealth of information about the kinetics of charge carriers. Such information, however, is very rarely obtained in a true sense, simply because these curves are not easy to interpret. There are diverse impediments to analyzing such curves. A few typical forms of relaxation curves. Parameters that influence the shape are discussed in the text. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203743522/378e7576-08b3-4f9c-9e71-d0301e1f339a/content/fig3_1_OB.tif"/>