Temperature dependent reversal of voltage modulated light emission and negative capacitance in AlGaInP based multi quantum well light emitting devices

TL;DR

This paper investigates how temperature variations cause a reversal in negative capacitance and voltage modulated light emission in AlGaInP multi-quantum well LEDs, revealing a complex interplay between defect participation and carrier escape.

Contribution

It demonstrates the temperature-dependent reversal of negative capacitance and modulated light emission, highlighting the importance of operating temperature for device efficiency.

Findings

Negative capacitance and modulated emission peak at a certain temperature.

Light emission behavior differs from constant increase with cooling.

Optimal device efficiency occurs when maximum emission temperature is matched.

Abstract

We report a reversal in negative capacitance and voltage modulated light emission from AlGaInP based multi-quantum well electroluminescent diodes under temperature variation. Unlike monotonically increasing CW light emission with decreasing temperature, modulated electroluminescence and negative capacitance first increase to a maximum and then decrease while cooling down from room temperature. Interdependence of such electronic and optical properties is understood as a competition between defect participation in radiative recombination and field assisted carrier escape from the quantum well region during temperature variation. The temperature of maximum light emission must coincide with the operating temperature of a device for better efficiency.