A 3D simulation comparison of carrier transport in green and blue c-plane multi-quantum well nitride light emitting diodes
Journal
Journal of Applied Physics
Journal Volume
128
Journal Issue
23
Date Issued
2020
Author(s)
Abstract
Until recently, the electrical efficiency of green nitride light-emitting diodes (LEDs) was considerably lower than that of blue LEDs. This is particularly surprising as one would expect a reduced forward voltage with increasing emission wavelength. In this paper, we theoretically investigated the impact of the number of quantum wells on the forward voltage of III-nitride LEDs with x = 0.15 (blue) and x = 0.24 (green) InxGa1-xN QWs. The simulated dependence of current density (J) on applied diode bias (V) shows a significant increase of 1.9 V in the forward voltage between one and five quantum well (QW) c-plane green LED structures. Artificially turning off the polarization fields in the simulation does not entirely suppress this effect. Due to the large band offsets in the green LED multiple QW (MQW) stack, simulations indicate a sequential band filling of the QW sequence. This mechanism should not be limited to c-plane LEDs and could also be present in nonpolar or semipolar devices. © 2020 American Institute of Physics Inc.. All rights reserved.
Other Subjects
Gallium alloys; Indium alloys; Light emitting diodes; Nitrides; Quantum chemistry; Semiconductor alloys; 3D simulations; Blue light emitting diodes; Carriers transport; Electrical efficiency; Forward voltage; Green light emitting diodes; Lightemitting diode; Multiquantum-well (MQW); Quantum-wells; Simulation comparison; Semiconductor quantum wells
Type
journal article