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arXiv · 1812.02443

Engineering decomposition-resilience and de-coalescence of GaN nanowire ensembles

Swagata Bhunia·Ritam Sarkar·Dhiman Nag·Kankat Ghosh·Krista R Khiangte·Suddhasatta Mahapatra·Apurba Laha
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Abstract

The rapidly increasing interest in nanowires (NWs) of GaN and associated III-Nitrides for (opto-)electronic applications demands immediate addressal of the technological challenges associated with both NW-growth and device processing. Towards this end, we demonstrate in this work an approach to suppress thermal decomposition of GaN NWs, which also serves to remedy the effect of NW-coalescence during growth. While both these effects are well-known to be major hurdles in the development of GaN-NW-devices, reliable methods to tackle these issues have not been reported so far. We show that by providing a thin AlN cap layer, which epitaxially grows only on the top-facet of the GaN NWs, thermal decomposition can be almost completely suppressed. Thermal annealing of GaN NW-ensembles, post AlN-capping, leads to selective decomposition of uncapped/partially-capped NWs, leaving behind (mostly) AlN-capped GaN NWs, with superior crystal- and luminescence characteristics. This simple yet extremely effective approach may therefore serve as a very crucial milestone in the roadmap of GaN-NW-based (opto-)electronic technology.

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Swagata Bhunia, Ritam Sarkar, Dhiman Nag, Kankat Ghosh, Krista R Khiangte, Suddhasatta Mahapatra, Apurba Laha. 2018-12-06. Engineering decomposition-resilience and de-coalescence of GaN nanowire ensembles. https://arxiv.org/abs/1812.02443

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