Growth of epitaxial p-type ZnO thin films by codoping of Ga and N

Abstract

Codoping of Ga and N was utilized to realize p-type conduction in ZnO films using rf magnetron sputtering. The films obtained at 550°C on sapphire showed resistivity and hole concentrations of 38Ωcm and 3.9×1017cm−3, respectively. ZnO films also showed a p-type behavior on p-Si with better electrical properties. ZnO homojunctions synthesized by in situ deposition of Ga–N codoped p-ZnO layer on Ga doped n-ZnO layer showed clear p-n diode characteristics. Low temperature photoluminescence spectra of codoped films also revealed a dominant peak at 3.12eV. The codoped films showed a dense columnar structure with a c-axis preferred orientation.

N Doping and Al-N Co-doping in Sol–Gel ZnO Films: Studies of Their Structural, Electrical, Optical, and Photoconductive Properties

“…15 There are other reports on Ga-N co-doping using radiofrequency (RF) sputtering and co-sputtering techniques. 16,17 According to theoretical predictions, Al-N co-doping has been found to be more effective than doping with Ga-N, since the corresponding III-N and III-O bonds are stronger for Al. 18 The reported Al-N co-doped p-ZnO films are mostly grown by the direct-current (DC) or RF sputtering technique.…”

Design of shallow acceptors in ZnO through early transition metals codoped with N acceptors

“…The traditional co-doping approach 9 by doping donor and acceptor simultaneously is another way to enhance the solubility of a dopant in ZnO. There have been several publications reporting on successful fabrication of codoped p-type ZnO 5, [10][11][12][13][14][15][16] , as well as failures [17][18][19] . However, the high ionization energy of acceptors, caused by the very low valence band maximum (VBM) of ZnO, is hard to overcome 20 .…”

Deposition and Performance Challenges of Transparent Conductive Oxides on Plastic Substrates

“…CuInO 2 -Ca [57]. Traditional n-type TCO material ZnO recently was made p-type by the codoping method with, for example, NIn, N-Al and N-Ga [58]. To deposit these different materials as p-TCO and p-TSO, a number of different processes, spray pyrolysis, PECVD, PLD and RF or DC sputtering, were used with substrate temperatures or post treatments (or both) ranging from $400 to 700 C.…”