Lift-Off of Semipolar Blue and Green III-Nitride nanoLEDs Grown on Free-Standing GaN

Abstract

Light-emitting diodes (LEDs), with active blue and green emitting and sacrificial multi-quantum well layers, were epitaxially grown using metal organic chemical vapor deposition on free-standing semipolar (2021) GaN substrates. NanoLEDs were then fabricated and released into solution using an approach based on forming a mm-scale mesa, Au–Au thermocompression bonding to a submount, large-area photo- electrochemical etching, and colloidal lithography. Photo- and cathodoluminescence (CL) measurements demonstrated that nanoLEDs were optically active after fabrication and released into the solution. Monte Carlo simulations of the electron trajectory through GaN/InGaN were performed to understand the patterns shown in CL images. The fabrication process developed herein could provide a viable route to highly efficient, nanoscale blue and green light emitters for applications in next-generation display technologies.