Investigation and direct observation of sidewall leakage current of InGaN-Based green micro-light-emitting diodes

Electrical and optical characteristics of InGaN-based green micro-light-emitting diodes (mu LEDs) with different active areas are investigated; results are as follows. Reverse and forward leakage currents of mu LED increase as emission area is reduced owing to the non-radiative recombination process at the sidewall defects; this is more prominent in smaller mu LED because of larger surface-to-volume ratio. Leakage currents of mu LEDs deteriorate the carrier injection to light-emitting quantum wells, thereby degrading their external quantum efficiency. Reverse leakage current originate primarily from sidewall edges of the smallest device. Therefore, aggressive suppression of sidewall defects of mu LEDs is essential for low-power and downscaled mu LEDs. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

The electrical and optical characteristics of InGaN-based green micro-light-emitting diodes (μLEDs) with different active areas were investigated. The results showed that the reverse and forward leakage currents of μLEDs increased as the emission area decreased, primarily due to the non-radiative recombination process at the sidewall defects. The leakage currents compromised the carrier injection to the light-emitting quantum wells, leading to a degradation in their external quantum efficiency. The reverse leakage currents were found to originate primarily from the sidewall edges of the smallest device. Therefore, aggressive suppression of sidewall defects is crucial for low-power and downscaled μLEDs.