Polychromatic Light Emission from Electrically Driven Single Pyramid Micro LED

W. Chen, G. Hu, J. Jiang, M. Liu, Y. Yang, P. Xiang, G. Hu, Y. Lin, X. Han, Z. Wu, Y. Liu, B. Zhang
State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, CN

Keywords: LED, micro, polychromatic, MOCVD, mechanism

Summary:

In recent years, the InGaN material system is of great interest for applications in production of monolithically integrated polychromatic LEDs for full-color display. Many groups have reported on the visible-color-tunable LEDs by selective area growth. Their electroluminescence color can be tuned continuously from red to blue by adjusting the external electric bias. However, there still exist some controversial luminescence mechanisms in the color tunable procedure with varied injection currents. From this point of view, it is necessary to fabricate electrically driven single pyramid micro-LED to explore the mechanism. In this work, we reported on the fabrication of electrically driven single pyramid μLED. Various photoluminescence colors were found on different parts of the pyramid, including green emission from tip and blue emission from sidewalls. Moreover, color tunable electroluminescence has been realized at varied bias voltages. The luminescence mechanism in the color tunable procedure of μLED under different bias was explored by injecting ultra-short pulsed current with appropriate duties. Finally, excellent optoelectronic characterization of the μLED was also confirmed by the current-voltage and electroluminescence measurement.