|Description||Master of Arts Oral Defense: Md. Kazi Rokunuzzaman|
Howard Lee, Ph.D. - Advisor
Zhenrong Zhang, Ph.D. - Co-Advisor
Investigation of Electrically Induced Light Emission in Epsilon Near Zero (ENZ) Heterostructure
Popular generation of light sources include light emitting diodes (LED), LASER, and photoluminescence etc. Usually, the light generated from these sources are due to the electron-hole recombination. By using plasmonic structure we can also generate highly confined light by exciting surface plasmon polariton (SPP) mode. SPP is a quasi-electromagnetic wave, propagates along the metal/insulator (M-I) interface. There are several ways to excite SPP among electrically driven SPP excitation is one of them. In electrically driven approach, researchers use metal-insulator-metal (M-I-M) to excite SPP. On the other hand, advanced materials whose real part of permittivity (“epsilon”) goes to zero is called Epsilon-Near-Zero (ENZ) materials and these materials exhibited unique optical characteristics. There are different materials exhibited ENZ properties. Indium tin oxide (ITO), a class of transparent conductive oxide (TCO), with high carrier density high (10-19-10-21 cm-3) is among one of the commonly used ENZ materials. In this research work as an alternate approach, ENZ material based heterostructure (ENZ-I-M) has been investigated to study the emitted light by electrical biasing. To take the advantage of unique ENZ properties, Au/ITO/HfO2/Au heterostructures have been fabricated and examined. When the hot electrons injected by the means of electrical biasing across the junctions of the heterostructure, they will emit the extra energy in terms of photons. The photons excite the ENZ mode in the ITO and can potentially be emitted and enhanced by the surface scattering or output coupling nanoantenna. This work provides insight on electrically-induced light emission from nanophotonic and ENZ structures, and will potentially lead to advanced nano-light sources for imaging, sensing, and communication applications.
Meeting ID: 840 0258 3228