Apparatus for Measuring Resistivity and Hall Coefficient of Semiconductors

TLDR

The paper presents an apparatus for measuring resistivity and Hall coefficient of semiconductors. The device employs a novel circuit that merges ac and dc techniques to eliminate thermal emf and Ettingshausen errors while retaining a simple dc potentiometer and galvanometer for null detection. Measurements on a germanium sample show that contact and lead resistances do not affect readings, demonstrating the apparatus’s accuracy.

Abstract

An apparatus for measuring resistivity and Hall coefficient of semiconductors is described. Using a new type of measuring circuit, it combines the best features of both ac and dc apparatus. Thus, on the one hand, errors due to thermal emf's and the Ettingshausen effect are eliminated while, on the other hand, the one necessary balance is still made on a simple dc potentiometer with a dc galvanometer as null indicator. Contact and lead resistances do not affect the readings. Results of resistance and Hall coefficient measurements on a germanium specimen are given as an indication of performance.