Growth of Cu2O thin films with high hole mobility by introducing a low-temperature buffer layer

The authors report the effect of a low-temperature buffer layer of Cu2O (LTB-Cu2O) on the growth of Cu2O thin films. The samples were prepared by radio frequency-magnetron sputtering. It was found that with the introducing of LTB-Cu2O, the linewidth of the X-ray diffraction peak decreases and the Cu2O thin films have preferred (1 1 1) orientation. By introducing LTB-Cu2O, the grain size sufficiently increases and the surface flatness improves, as indicated from the atomic force microscopy measurement. Under the optimum growth conditions, hole mobility of 256 cm2 V−1 s−1, which is the highest value reported so far, with the hole concentration of 1×1014 cm−3 was achieved.