SnGe superstructure materials for Si-based infrared optoelectronics

We report growth of device-quality, single-crystal SnxGe1−x alloys (with x=0.02–0.2) directly on Si via chemical vapor deposition with deuterium-stabilized Sn hydrides. The high Sn-content materials are stabilized with ordered superstructures that gives rise to a layered structure adjacent to the Si substrate. Density functional theory simulations were used to elucidate the structural and bonding behavior of this material. Optical determinations show a Ge-like band structure that is substantially redshifted compared to that of elemental Ge. Thus, these systems are excellent candidates for a new generation of infrared devices, with the critical advantage that they can be grown directly on Si.