n-type and p-type semiconducting Cu-doped Mg (OH)2 thin films

Cu-doped Mg(OH)(2) thin films are deposited electrochemically from an aqueous solution and annealed in air at 400 degrees C. The deposition solution contains Mg(NO3)(2) and Cu(NO3)(2). UV-visible experiments show high transmission larger than 90% for all the samples. According to x-ray photoelectron spectroscopy results, copper is in the Cu1+ charge state for as-deposited films whereas after annealing, its state is a mixture of Cu2+ and Cu1+. Those films are found to be amorphous by x-ray diffraction. n-type conductivity is identified for the as-deposited films by photoelectrochemical characterizations, and resistivity is of the order of 10(3) or 10(4) Omega cm. The annealed films are p-type or intrinsic with high resistivity of the order of 10(5) Omega cm. Thus, both n-type and p-type Mg(OH)(2) semiconductor films are fabricated with Cu doping and will be possibly applied for transparent electronics. According to the first-principles calculation, origin of n-type conduction could be Cu atoms at the interlayer sites whereas p-type conduction could be due to substitutional Cu.