Experimental evidence of magnetically controlled surface current in hall devices

A previously unknown galvanomagnetic effect in semiconductors (conducting materials) within wide temperature range (77–300 K) has been experimentally observed, which is expressed by the appearance of magnetically controlled currents on the opposite lateral boundaries of structures between which Hall voltage is also generated. Surface currents are a linear and odd function of the strength and direction of both the bias current and the magnetic field – if the direction of the magnetic field or the supply current is reversed, the polarity of the surface current will also change. This unexpected surface phenomenon is a direct demonstration of the action of the Lorentz force on the moving charges in semiconductors. The discovered mechanism can enrich the possibilities for surface characterization and rapid determination of the main parameters in solids, such as conductivity type, carrier concentration and carrier mobility. The dependence of the surface current in solids on various nonelectrical quantities is useful for development of new types of sensors for pressure, light, chemical composition etc.