Use of Gold Nanoparticles in Indium Gallium Nitride Growth for Improving the Photoactive Electrical Performance of p-n Junctions

In this report, the results of indium gallium nitride (InGaN) grown by chemical vapor deposition (CVD) on a sapphire substrate covered by gold nanoparticles (AuNPs) are discussed. AuNPs were formed by solid-state dewetting from a thin gold film. The samples on AuNPs were compared with a series of InGaN films grown with the two-step method. X-ray diffraction (XRD) and Raman spectroscopy expose higher indium incorporation in InGaN on AuNPs than in films grown by the two-step method. The effect of AuNPs on the surface morphology and compactivity of InGaN films was studied by scanning electron microscopy (SEM). An energy reduction of the absorption band edge was evidenced by UV-vis spectroscopy diffuse reflectance (DFR) and absorbance. Photoluminescence (PL) and cathodoluminescence (CL) revealed a passivation in the intensity of the near-band emission (NBE) in the InGaN/AuNPs films. An increase in the density current of 127-182 μA/cm² in the gold-nucleated InGaN-based p-n junction was obtained by the induced localized surface plasmon resonance (LSRP) effect and the enhancement of InGaN phase stability. The implementation of AuNP-covered substrates in the growth of group III nitrides can be an alternative for improving InGaN phase miscibility and imparting suitable properties for photovoltaics applications aiming to achieve high-efficiency InGaN-based solar cells.