Negative Capacitance Analysis of Multi-Quantum-Well Light-Emitting Diodes

• DOI: 10.3390/electronics14030413
• Publication Date: 2025-01-21T10:47:42Z
• Authors: Yang Xiao; Xiaoyu Feng; Yuan Meng; Longzhen He; Pengzhe Zhang; Dongyan Zhang; Shoushuai Gao; Philip Shields; Haitao Tian; Hongwei Liu

To explain the negative capacitance (NC) characteristic of multi-quantum-well (MQW) LEDs, we calculated continuity equation for a 10-period AlGaInP/GaInP LED with mesa size 90 × 150 μm and build an MQW capacitor model. The carrier concentrations capacitance–voltage characteristics across every quantum well region were analyzed by accounting spontaneous, Auger, SRH recombination. In our model, dynamic lifetime iteration method iterative error less than 1 10−14 ns was used to decouple electric field variables in equation, providing new way enhance accuracy continuous equations. Based on concentration MQWs, derived multilayer epitaxial material equivalent circuit. theoretical model characterizes phenomenon at 1.75 V, which is consistent actual test results sample. Our analysis indicates that mainly comes from recombination region. Under low-frequency AC bias conditions, becomes more obvious. This work provides useful reference analyzing bandwidth LEDs fields display dimming visible-light communication.