Unijunction transistor (UJT) is a semiconductor with two ohmic base contacts and an emitter p-n junction, so it is called double-base diode. Its static(S-shaped) I-V characteristic has a region with negative differential resistances. Therefore, UJTs are used in pulse generators, sawtooth generators and converters. UJT-based circuits are well known to be simpler and more reliable than those based on diodes and bipolar transistors.
Recently, transducers where the output signal frequency depends on physical quantities such as temperature, light, magnetic field, stress, concentration of gas and radiation level, have been designed with UJTs. Thus, improvement of the switching characteristic of UJT leads to that of the characteristics of these transducers.
To improve the switching characteristic of UJT, a number of researchers have investigated the radiation effect on it. To the best of our knowledge, there are no reports in the literature regarding how the neutron irradiation of UJT affects its peak point voltage.
Pae Kyong Il, a researcher at the Semiconductor Institute, has proposed a new analytical expression for the peak point voltage of UJT considering the effect of neutron irradiation, and proved its validity by comparing the calculated values and those measured from the neutron irradiation on an Si planar UJT.
His study has shown that the calculated values of the peak point voltage of UJT are in good agreement with the measured ones, that the peak point voltage of UJT decreases after neutron irradiation, and that the peak point voltage of UJT decreases gradually with the growing intensity of neutron fluence.
© 2021 KumChaek University of Technology