p-type InN and in-rich InGaN

Capacitance-voltage (CV) measurements using a liquid electrolyte as rectifying contact were used to provide definitive proof of p-type activity beneath a surface inversion layer in Mg-doped InN and In-rich InGaN. Analysis of CV data using the Poisson equation allows net charge as a function of depth to be determined. In undoped InN, good agreement of the net donor concentration below the surface accumulation layer with bulk Hall effect data is obtained. In Mg-doped InN and InGaN, the CV data are shown to be consistent with the presence of a net acceptor concentration N A - N D near 10 19 cm -3 below a surface inversion layer.