**4.2. Majority carrier emission rates**

The simplest way in which the DLTS technique can be used is the measurement of majority carrier emission. The pulse sequence used is shown in Figure 1b, along with the band diagram and the capacitance transient resulting from such a sequence. The bands have been assumed to be flat for simplicity. The method consists of employing a sufficiently large bias over the sample so as to overcome the edge effects and at the same time be small enough to of lesser value than the break down voltage of the semiconductor. The sample is cooled below the starting measurement temperature. Now bias pulses close to zero volt are repeatedly applied while the sample is reheated. During the pulses, the levels are filled with majority-carriers. As soon as the sample returns to the quiescent reverse bias, the levels start emitting resulting in a transient. During the transient, the capacitance is measured at the pre-set rate window and the DLTS output is plotted as a function of the temperature. Thus we get a peak for each level which has an emission rate within the pre-set time window in the temperature range of scan. The temperature dependence of the emission rate is determined by observing the peak position for several different time windows.
