Structural and electrical characteristics of GaN, n GaN and A1 x Ga 1 x N
Abstract GaN, n GaN (n~ 1 x 10 18 /cm 3 and Al x Ga 1 x N (x 0. 14, 0.26, 0.45) were epitaxially grown by metal organic chemical vapor deposition (MOCVD) on c plane sapphire substrate. The composition and thickness of Al x Ga 1 x N layers were found by employing o 2th scan with simulation fit. The dislocation densities of epilayers were determined from symmetric and asymmetric planes of o scan rocking curve. The (105) plane reciprocal space mapping was employed to measure the in plane strain (e xx of the Al x Ga 1 x N layers grown on GaN. The in plane strain of GaN and n GaN were calculated from 2th scan. The second derivative of the capacitance of the AFM tip sample system was determined using electrostatic force microscopy (EFM) Photon decay time was measured using time resolved photoluminescence and the results correlated with structural property of the epilayers. The Schottky behavior of Ni/Au contacts on grown layers were studied using current voltage (I V) measurements. The Schottky barrier height of each device was compared with the edge dislocation density of the layers.