Switching of magnetoresistive light-emitting diode by external magnetic field

Abstract

A magnetic switch consisting of an integrated magnetoresistive element and a light-emitting diode has been developed and investigated. Switching the state of a magnetoresistive part allows one to control the electron vs hole current ratio in a light-emitting diode. In the high-resistance state, the hole current is high enough to trigger the electroluminescence. Switching to a low-resistance state decreases the hole current drastically, thus completely switching off the light-emitting diode. The effect was found to be strongly dependent on the operating current of the integrated circuit. We believe that the observed effect has multiple applications as a high-speed magnetic field sensor with an opto-coupler, a magnetic field visualizer, or an optical device for reading magnetoresistive random access memory.