Circumventing the miscibility gap in InGaN nanowires emitting from blue to red

• Published in: Nanotechnology Vol. 29; no. 46; p. 465602
• Main Authors: Roche, Elissa, André, Yamina, Avit, Geoffrey, Bougerol, Catherine, Castelluci, Dominique, Réveret, François, Gil, Evelyne, Médard, François, Leymarie, Joël, Jean, Theo, Dubrovskii, Vladimir G, Trassoudaine, Agnès
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 16.11.2018; Institute of Physics
• Subjects: compositional tuning; Engineering Sciences; growth modeling; HVPE; InGaN; nanowires; Optics; photoluminescence; Photonic
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/aaddc1

Widegap III-nitride alloys have enabled new classes of optoelectronic devices including light emitting diodes, lasers and solar cells, but it is admittedly challenging to extend their operating wavelength to the yellow-red band. This requires an increased In content x in InxGa1−xN, prevented by the indium segregation within the miscibility gap. Beyond the known advantage of dislocation-free growth on dissimilar substrates, nanowires may help to extend the compositional range of InGaN. However, the necessary control over the material homogeneity is still lacking. Here, we present InxGa1−xN nanowires grown by hydride vapor phase epitaxy on silicon substrates, showing rather homogeneous compositions and emitting from blue to red. The InN fraction in nanowires is tuned from x = 0.17 up to x = 0.7 by changing the growth temperature between 630 °C and 680 °C and adjusting some additional parameters. A dedicated model is presented, which attributes the wide compositional range of nanowires to the purely kinetic growth regime of self-catalyzed InGaN nanowires without macroscopic nucleation. These results may pave a new way for the controlled synthesis of indium-rich InGaN structures for optoelectronic applications in the extended spectral range.