A time-resolved optical system for spatial characterization of the carrier distribution in a gate turn-off thyristor (GTO)

The measurement of two-dimensional (2-D) excess-carrier distribution in a gate GTO by a time-resolved infrared-absorption technique is discussed. The optical scanning system employs a wide memory digital oscilloscope for data acquisition and a computer system for control, data processing, and display. Maps of the carrier distribution in the active GTO device are produced under steady-state conditions as well as during turn-on and turn-off operation. The maps are presented as three-dimensional (3-D) views produced from 2-D measurements.<
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