Structure and Photoelectric Performance of Al-Doped Copper Nitride Thin Films Prepared by Magnetron Sputtering

Aluminum-doped copper nitride(Cu₃N:Al)thin films were prepared on monocrystalline silicon and quartz wafers by dual-target co-sputtering magnetron technology with high-purity copper and aluminum as targets,nitrogen and argon as source gas and working gas,respectively.The surface morphology,crystal structure,light transmittance and electrical properties of the Cu₃N:Al thin films were characterized and analyzed.The results show that the doped Al atoms enter the vacancies of the lattice of the Cu₃N.With the increase of DC sputtering power on Al target,the content of Al in the Cu₃N:Al thin films increases.Al doping increases the particle size of the thin films,and the surface of the films becomes rough.The Cu₃N:Al thin films exhibit semiconductor characteristics,and their optical band gap ranges from 1.41 to 1.80 e V.After Al doping,the optical band gap of the Cu₃N thin films decreases.The reason is that the doping of Al atoms changes the lifetime of non-equilibrium carriers in the crystal,resulting in a decrease in the optical band gap of the thin films.It can be seen that by adjusting the content of doped metal atoms in the Cu₃N thin films,the photoelectric performance of the Cu₃N thin films can be modulated.