Green Electroluminescence from Radial m-Plane InGaN Quantum Wells Grown on GaN Wire Sidewalls by Metal–Organic Vapor Phase Epitaxy

Abstract

We demonstrate green emission from InGaN/GaN multiple quantum wells (MQWs) grown on m-plane sidewalls of GaN wires. To tune the emission wavelength, InGaN radial wells were grown by metal–organic vapor phase epitaxy (MOVPE) at decreasing temperatures ranging from 710 down to 620 °C to increase the In incorporation. A comprehensive investigation combining structural and optical analyses demonstrates that the green emission from the nonpolar m-plane wire sidewalls is achieved for the wells grown at 650 °C (namely, for 2.7 nm thick wells sandwiched by 11 nm thick GaN barriers). The observed emission wavelength of 500–550 nm is consistent with an average In-content of MQWs measured in the range of 24 ± 4% by energy dispersive X-ray (EDX) and atom probe tomography (APT). Single wires were electrically contacted and the green electroluminescence from m-plane facets was established on single wire-LED devices. This demonstrates the possibility to produce green emitters with core–shell wire LEDs elaborated by industrial and scalable MOVPE technique.

Colour optimization of phosphor-converted flexible nitride nanowire white light emitting diodes

“…Then, the core/shell heterostructures are grown at a lower temperature that consists of the active region of seven InGaN/GaN MQWs covered with an Mg-doped p-GaN shell. The emission colour of the LED can be tuned by varying the growth temperature of the InGaN MQWs leading to a different In concentration, keeping constant the temperature at 885°C to grow GaN barriers [26]. For this study, two samples with different targeted In content were grown using the MQW growth temperatures of 750°C (emission in the range of 400-450 nm) and 680°C (emission in the range of 450-500 nm).…”

UV Emission from GaN Wires with m-Plane Core–Shell GaN/AlGaN Multiple Quantum Wells

“…Core-shell systems have been intensively studied in the case of InGaN/GaN MQWs for the development of wire-based LEDs in the blue-green spectral range. [18][19][20] Focusing on wires for UV emission grown by MOVPE, we can distinguish core-shell structures with three types of inner core: AlN 10-12 , AlxGa1-xN (x<0.35) 13, 14 and GaN [15][16][17] .…”

Structural and optical impacts of AlGaN undershells on coaxial GaInN/GaN multiple-quantum-shells nanowires

“…An independent phenomenon with dislocation density was observed in GaInN/GaN LEDs under high-current recombination terms [22], while the point defects mainly contributed to the nonradiative recombination process in the current density range of 10 −2 -10 A/cm −2 [23]. To date, most of the work reported on GaN-based NWs has focused on the growth mechanism and the optically pumped and electrically injected properties [7,[24][25][26]. However, less emphasis has been placed on the elimination/suppression of point defects diffusion in GaN-based NWs.…”