The Generator folder allows the pulse parameters and sequence of pulses to be defined. When the generator output is disabled it means that a constant 0V applied to the sample. There are some functions in the system preventing a user from applying an uncontrolled bias to the sample. Always when a new system configuration is loaded and the new sample bias is larger than the current one then the DC generator output is disabled and a user is notified. The lowest value of the reverse bias depends on the hardware as defined in the Lap_sys.ini file. All parameters of the Generators are stored in the configuration file.
When the second pulse (Pulse 2) is enabled then after the acquisition of the transient following the first pulse the second pulse is to the sample applied and the transient is recorded. The acquisition parameters are for both pulses the same and the transients are recorded differentially, i.e. from each value of the signal sample following the first pulse the corresponding value of the signal sample after the second pulse is subtracted. In this way the difference between these two transients is recorded. This mode of the measurement allows to investigate a spatial distribution of defects in the space charge region or to observe the influence of the electric field on the emission process. When the test transient is recorded it is always, i.e. no matter the pulse 2 is enabled or not, the one which follows the pulse 1.
A way how these two pulses are interlaced can be modified from full interlacing, i.e. when each pulse 1 is followed by the pulse 2, to no interlacing at all when a series of pulse 1 is completed the same number of the pulse 2 is applied and the recorded transients are subtracted. NOTE: a more intensive interlacing means that the hardware has to be reprogrammed during the measurement more times, and this makes the over-all time of the measurement longer. The number of the interlaced pulses can be changed on the Customise form.
When the ‘Like 1’ box is checked then the duration of the second pulse (Pulse 2) is the same as of the first one.
The pulse 1 prime is applied to the sample immediately after the pulse 1 completes. The acquisition process starts after the pulse 1 prime. Combination of the pulse 1 prime with the pulse 1 allows to measure effects related to the presence of minority carriers in the sample or an influence of light on the emission process.