A Study of Electro-Optic Materials Properties towards Multifunctional Materials

The push towards miniaturization and higher speeds in electronic devices has spurred a search for the identification and development of new multifunctional materials. Materials exhibiting more than single electrical, optical, magnetic, elastic, or other characteristic response, are known as multifunctional materials. These materials provide the possibility of integrating multiple functional properties, along with entirely new properties arising from cross-coupling, into a single system. Such multifunctional materials can be classified into a large number of systems including compound semiconductors, dilute magnetic semiconductors, colossal magneto resistive materials multiferroic materials. As a specific example of how multifunctional materials can be used to develop new devices, we consider new compound semiconductors for optoelectronic applications. Si, elemental semiconductor, was crucial for building the modern electronic industry. However Si is an indirect band gap semiconductor and thus is not an efficient light emitter or absorber. Photovoltaic and optoelectronic devices require a strong interplay between photons and electrons. Direct bandgap semiconductors are more suitable for such applications which show strong absorption or emission for the desired electromagnetic spectral range. III-V and II-VI compound semiconductors are widely used in optoelectronic devices e.g. infrared and visible light emitting diodes (LEDs), optical fiber communications and high efficiency solar cells, precisely because of the stronger coupling between the semiconducting and optical properties in these materials.