Session B39: Focus Session: Materials and Applications for Solar Energy I
11:15 AM–2:03 PM, Monday, March 5, 2007
Colorado Convention Center Room: 502
Sponsoring Units:
FIAP DMP
Chair: Mike McGehee, Stanford University
Abstract ID: BAPS.2007.MAR.B39.4
Abstract: B39.00004 : P-type InGaN alloys
12:15 PM–12:27 PM
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Abstract 
Authors:
D.M. Yamaguchi
(U.C. Berkeley, Berkeley CA, 94720,; Berkeley Lab, Berkeley CA, 94720)
R.E. Jones
(U.C. Berkeley, Berkeley CA, 94720,; Berkeley Lab, Berkeley CA, 94720)
N.R. Miller
(U.C. Berkeley, Berkeley CA, 94720,; Berkeley Lab, Berkeley CA, 94720)
E.E. Haller
(U.C. Berkeley, Berkeley CA, 94720,; Berkeley Lab, Berkeley CA, 94720)
J.W. Ager
(Berkeley Lab, Berkeley CA, 94720)
K.M. Yu
(Berkeley Lab, Berkeley CA, 94720)
W. Walukiewicz
(Berkeley Lab, Berkeley CA, 94720)
H. Lu
(Dept. of Electrical and Computer Engineering, Cornell University, Ithaca, NY)
W.J. Schaff
(Dept. of Electrical and Computer Engineering, Cornell University, Ithaca, NY)
We have demonstrated via electrolyte-based capacitance-voltage (CV) measurements that a set of Mg-doped In$_{1-x}$Ga$_{x}$N thin films (x=.05,.30,.33,and .80) exhibit bulk p-type activity. There is a change in the slope of the Mott-Shockley plots of In$_{1-x}$Ga$_{x}$N with x $\le $ .33 which is consistent with p-type bulk material underneath an n-type surface inversion layer. In contrast, CV analysis of Mg-doped In$_{0.2}$Ga$_{0.8}$N indicates p-type activity throughout the film. These results are consistent with surface Fermi level pinning at --4.9 eV with respect to the vacuum level. Based on the known valence band offsets between GaN and InN, a surface inversion layer is predicted for In$_{1-x}$Ga$_{x}$N with x $\le $ .66 and a surface Schottky barrier for x $>$ .66. These results provide the first evidence of p-type doping of InGaN alloys in the whole composition range.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.B39.4