Effect of Quantum Confinement on Electrical Properties in GaInP Semiconductor Laser Diode Structures

Abstract

The effect of quantum confinement on electrical properties in GaInP semiconductor laser diode structures is investigated. The GaInP semiconductor laser was grown on GaAs substrate using the Molecular Beam Epitaxy (MBE) technique. The devices structures used in this study contain either bulk, quantum well, or quantum dot layers that are all made of GaInP material. The variation between these structures is found in the degree of confinement for the carriers in these structures. Several electrical parameters, such as series resistance (Rs), reverse saturation current density (Js), ideality factor (n), barrier height (∅Bo), and activation energy (Ea), are calculated depending on the measurements of the current-voltage characteristic (I-V) at the temperature range of 77 K to 400 K with a stepping of 25 K. The effect of quantum confinement causes a decrease in Rs and a rise in Js values due to high carrier transition efficiency. However, an increase to n due to the existence of barrier walls that account for the carrier's field emission. This is the main reason for the high n in the structure. The value of ∅Bo decreases with increasing quantum confinement. It depends strongly on the temperature and shows an inverse behavior to n variation with temperature. The phenomenon of quantum confinement effectively enhances carriers' mobility as it modifies the transition through energy states. This results in higher efficiency of carriers' transition, consequently leading to a decrease in Ea as the confinement increases. The values of Ea are approximately equal to the lower values of ∅Bo for all studied structures.