pH sensing using growth of InN nanorods on glass substrates

In this work, the sensing cell of pH sensors with an vertically aligned InN nanorods array with a uniform diameter and length was fabricated on a glass substrate by plasma-assisted molecular beam epitaxy. The nanorod diameters were measured to be between 60 and 150 nm and have a length of around 500 nm.The InN nanorods with high crystalline quality grow preferentially in the (0002) direction over a large area. The resulting pH sensors with InN nanorods exhibited significantly improved sensing performances owing to the large sensing surface-tovolume ratio. The pH sensitivity calculated from the linear relation between the cyclic voltammetry current and the pH value was 5.4 nA/pH.