The power diode construction is much different from normal diode. The main difference is due to addition of a new region in normal diode, the drift region. This region will provide space needed to take care of depletion region which is created as a result of reverse bias. The power diode construction employs a vertical structure in which different microelectronic processes are utilized to complete the structure. The doping construction is kept very high on anode and cathode to take care of large currents that will flow through the device during forward bias ... https://www.youtube.com/watch?v=1NDFdx_aZQM

This video outlines all the operations that take place when the thyristor is applied input on the gate signal. ... https://www.youtube.com/watch?v=EytNHjKStdw