Electromotive Force of Spontaneously Polarized Semiconductors

Abstract

Background: Spontaneously polarized finely dispersed semiconductors can be sources of direct electric current, similar to thermoelectric converters. Their power is low due to the low electrical conductivity of the powders. Objective: Theoretical description of the electromotive force of a spontaneously polarized homogeneous semiconductor film with ionized donor centers uniformly distributed over its two surfaces and free electrons in the volume. Establishment of technical characteristics and competitive advantages of using a film as a current source converts the received energy (heat or light) into the work of an electric field. Methods: The theory of semiconductors and the laws of thermodynamics are used. Results: Analytical expressions are obtained that describe the electronic processes in a metal-semiconductor-metal three-layer film and the technical characteristics of its use as a current source. Estimates are given on the example of a silicon film with arsenic-doped surfaces. Conclusion: The universal principles for creating homogeneous solids of macroscopic dimensions are substantiated, with the efficiency of converting heat into the work of an electric field, which is significantly (by an order of magnitude) higher than the efficiency of materials used to create thermo-EMF sources. The heat absorbed by the metal-semiconductor-metal three-layer film serves as an energy source for a direct current in a closed circuit generated by this structure with an efficiency of 100%. The power of the current source 10 - 105 W/m depends on the received heat flow. A semiconductor film with a built-in electric field is an analogue of a p - n junction and does not have its drawbacks.