Influence of (CH[sub 3])[sub 2]NHBH[sub 3] Concentration on Electrical Properties of Electrochemically Grown ZnO Films

Abstract

Zinc oxide (ZnO) films have been deposited on nonconductive glass substrates by chemical deposition followed by electrochemical growth in zinc nitrate [Zn(NO3)2⋅H2O][Zn(NO3)2⋅H2O] aqueous solutions containing dimethylamine-borane (DMAB) at 333 K. The effect of DMAB concentration on the structural and electrical characteristics was investigated by inductively coupled plasma analysis, X-ray diffraction, and Hall measurement. The increase in DMAB concentration gave a decrease in resistivity and an increase in carrier concentration and mobility. The boron content in the ZnO film increased with an increase in DMAB concentration. The 1.5 μm thick ZnO film with a maximum boron content of 1.1 atom % was obtained at the cathodic potential of −0.8 V from a 0.1 mol/L zinc nitrate aqueous solution with 0.1 mol/L DMAB. This film had a resistivity of 7.8×10−3 Ω cm,7.8×10−3 Ω cm, carrier concentration of 1.2×1019 cm−3,1.2×1019 cm−3, and mobility of 86 cm² V⁻¹ s⁻¹. Boron ions originating from DMAB acted as donors for the ZnO film and gave the lattice expansion. © 2001 The Electrochemical Society. All rights reserved.