Vol. 43, Issue 1, pp. 35-38 (2013)
Keywords
sensor, AlGaN/GaN heterostructure, electrolyte, two-dimensional electron gas (2DEG), pH
Abstract
In the paper, the behavior of AlGaN/GaN HEMT-type heterostructures in a water solution of (KOH + HCl) with differing pH was studied. The influence of the electrolyte pH on channel pinch-off voltage was measured using impedance spectroscopy methods. It was observed that the change of the pH of electrolyte has a strong effect on the pinch-off voltage of AlGaN/GaN HEMT-type heterostructures independently of the concentration of other ions. In high-pH environment the so-called memory effect of heterostructures was revealed. Its possible origin was discussed. A general theory to explain all results was proposed.