Accumulation and exclusion of excess carriers observed in inhomogeneous germanium samples

Abstract

IR probing measurements of germanium samples are presented, showing, according to the theory [1], accumulation and exclusion effects due to current flow through an internal built-in electric field appearing in the inhomogeneous part of the crystal.

The transport of excess current carriers in an inhomogeneous semiconductor with position-dependent band gap

“…The built-in field is the gradient of an electrostatic potential (gradV 0 ) existing in an inhomogeneous semiconductor in equilibrium (no excess carriers). This field also influences the distribution of excess carriers, increasing accumulation or exclusion in structures with l-h junctions, which is shown in [5] and [6].…”

Exclusion in the semiconductor p+-p-p+structure under conditions of a temperature gradient

“…Investigations of exclusion under conditions of an inhomogeneous electric field enabled new interesting and practical aspects of this phenomenon to be revealed. An initial inhomogeneous electric field in the sample was created by its unusual spherical or cylindrical geometry [1][2][3], then by an inhomogeneous impurity distribution [4,5] and finally by using a semiconductor with a varying forbidden gap [6]. It has been shown that the built-in electric field introduces qualitative changes to the exclusion-accumulation characteristics of the sample.…”

“…In [1][2][3][4][5][6] an inhomogeneous electric field in the structure was obtained by either additional technological processes (fabrication of varying gap structures, inhomogeneous doping) or a complicated shape of the sample. Apart from that, the given value of grad E remains constant during investigations.…”