Impact of Cu addition on the optoelectronic properties of Zn₃N₂ thin films: n to p-type transitions

Copper-doped Zinc Nitride (Cu:Zn3N2) films are grown on glass and Si substrates at various concentration of Cu (2.7, 4.9 and 5.7 at.%) by reactive RF magnetron co-sputtering. The impact of Cu atomic concentration on the structural and optoelectronic properties of Zn3N2 films is discussed in detail. Incorporation of Cu ions into Zn3N2 host lattice is confirmed by EDAX analysis. Hall Effect results indicate that the fabricated film exhibited p-type conductivity with high hole concentration of 1.78-1.36 x 10(18) cm(-3) , resistivity of 0.48-0.56 Omega cm, and high hole mobility of similar to 8 cm(2) V(-1 )s(-1). The transmittance of Cu:Zn3N2 films are found to be in the range of 11-18% at the wavelength of 500 nm and hence the band gap decreases from 1.80 to 1.61 eV when Cu doping content is increased. These findings would assist Cu:Zn(3)N(2 )as a potential candidate for p-type layer in thin film solar cells.