Improvement in the accuracy of determining impurity compensation in pure weakly compensated germanium from breakdown-field strength

Abstract

It is shown that measurement of the electric-breakdown field E_br in a classically high magnetic field (H) at T = 4.2 K makes it possible to determine the value of the degree of compensation K in pure germanium with K < 50% much more precisely than at H = 0. The parameter S = E_br/H is introduced and its dependence S = f(K) is calculated; the obtained curve makes it possible to determine K if H and E_br are known. To decrease the resistance of the samples, it is recommended that measurements be carried out under “impurity” illumination. It is shown that the value of E_br is invariable at low intensities of such excitation.