Strain-Modulated Light Emission Properties in a Single InGaN/GaN Multiple-Quantum-Well Microwire-Based Flexible Light-Emitting Diode

Micro/nanowire light-emitting diodes (LEDs) have inspired considerable research interests due to their potential applications in microdisplays and micro/nano-optoelectronic integrated systems. Herein, a single InGaN/GaN multiple-quantum-well (MQW) microwire-based flexible LED with high-efficiency current injection and spreading is fabricated, and the performance modulation of the device by external strain is further studied. The results show that under external compressive strains, the output power is enhanced and the peak wavelength is blue shifted; on the contrary, the output power declines and the peak wavelength is red shifted under stretch strains. Compared with strain-free devices, the flexible LED achieves the best performance at a - 1% compressive strain, with external quantum efficiency (EQE) increasing by 14.2% and efficiency droop reducing by 17.9%. The effective improvements are attributed to external strain-induced piezoelectric polarization charges presented at local junctions/interfaces tuning the energy band. Herein, an efficient external modulation of light emission properties in a single InGaN/GaN MQW microwire LED is presented.

Automated summary

A flexible LED based on multiple quantum well microwires is fabricated and its performance is modulated by external strain. The best performance is achieved at -1% compressive strain, with increased external quantum efficiency by 14.2% and reduced efficiency droop by 17.9%, attributed to strain-induced piezoelectric polarization charges tuning the energy band structure.