Practical Materials Chemistry Approaches for Tuning Optical and Structural Properties of Group IV Semiconductors and Prototype Photonic Devices

We report new approaches based on rational design and preparation of chemical vapor deposition precursors involving novel main-group hydrides to fabricate new families of Si-based semiconductors and prototype devices that display compositional and structural inheritance, from the parent molecule to the solid end product. This methodology enables materials synthesis at extraordinarily low temperatures that are compatible with complementary metal-oxide-semiconductor (CMOS) processing/selective growth and provides the means for obtaining highly metastable strain states in prototype structures that cannot be obtained by conventional protocols. Some of the materials and devices under development, involving alloys in the Si-Ge-Sn system, open up exciting opportunities in photodetectors and photovoltaics because they grow directly on cheap Si substrates and cover an extended range of the near-infrared spectrum that is not accessible to current photovoltaic and optoelectronic group IV semiconductors.