DEVICE FOR MEASUREMENT OF SURFACE PHOTO-EMF OF SEMICONDUCTORS Russian patent published in 1994 - IPC

FIELD: semiconductor technology. SUBSTANCE: the device has pulsed light source 1, capacitor cell 2 with a semitransparent electrode, pulse amplifier 3, indicator 4, synchronizer 5, test pulse generator 6, first controlled commutator 7 with reversal of output voltage polarity, second controlled commutators with reversal of output voltage polarity, comparison circuit 9, reference signal unit 10, comparator 11, resistor 12, first controlled electronic switch 13, second controlled electronic switch 14 and third controlled electronic switch 15. The pulse amplifier is made controllable, and its control input is connected to the comparison circuit output, and the output is additionally connected to the comparator input, whose output is connected to the control inputs of the first and second commutators. The inputs of the second and third controlled electronic switches are connected via the semitransparent electrode of the capacitor cell. The output of the third controlled electronic switch is connected to the input of the pulse amplifier. The synchronizer first output is connected to the synchronizing input of the test pulse generator, the second input - to the control inputs of all electronic switches, and the third output - to the synchronizing input of the pulsed light source. EFFECT: enhanced accuracy of measurement of value and determination of polarity of surface photo-emf. 1 dwg