Electrocatalytic oxidation enhancement at the surface of InGaN films and nanostructures grown directly on Si(111)

• Published in: Electrochemistry communications 2015-11, Vol.60, p.158-162
• Main Authors: Soto Rodriguez, Paul E.D., Nash, Veronica Calderon, Aseev, Pavel, Gómez, Victor J., Kumar, Praveen, Alvi, Naveed Ul Hassan, Sánchez, Alfredo, Villalonga, Reynaldo, Pingarrón, José M., Nötzel, Richard
• Format: Article
• Language: English
• Subjects: Cyclic voltammetry; InGaN; InN; Nanocolumns; Nanowall network; Quantum dots
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2015.09.003

Pronounced electrocatalytic oxidation enhancement at the surface of InGaN layers and nanostructures directly grown on Si by plasma-assisted molecular beam epitaxy is demonstrated. The oxidation enhancement, probed with the ferro/ferricyanide redox couple increases with In content and proximity of nanostructure surfaces and sidewalls to the c-plane. This is attributed to the corresponding increase of the density of intrinsic positively charged surface donors promoting electron transfer. Strongest enhancement is for c-plane InGaN layers functionalized with InN quantum dots (QDs). These results explain the excellent performance of our InN/InGaN QD biosensors and water splitting electrodes for further boosting efficiency. [Display omitted] •Pronounced electrocatalytic oxidation enhancement at the surface of InGaN layers and nanostructures directly grown on Si by plasma-assisted molecular beam epitaxy is demonstrated.•In cyclic voltammetry measurement, the potential of the anodic current peak is given by the In content, i.e., the density of positively charged surface donors and the peak current is governed by the area of active c-plane.•InN QDs are designed active sites to strongly enhance the electrocataclytic behavior.•Optimum balance between catalytic activity driving the reaction and surface area increasing the amount is understood.