Supersaturating Silicon with Titanium by Continuous-Wave Laser Irradiation of Sputtered Titanium Film on Silicon

A method of magnetron sputtering followed by continuous-wave (cw) laser irradiation is developed to prepare crystalline silicon supersaturated with titanium. The irradiation of single crystalline Si samples sputtered with a thin layer of Ti is carried out under the 1064 nm cw laser in a specially designed home-made facility. The thickness of the Si layer, within which the concentration of Ti surpasses the Mott limit, reaches 365 nm and the maximum concentration of Ti reaches 1.83 × 10²¹ cm⁻³. The crystalline structure of the Si samples is kept unchanged after cw laser irradiation. These results show that the current method can be an efficient way to obtain an intermediate band semiconductor material for solar cells. (paper)