Broad Research Interest: Heterogeneous Integration Research Group (HIRG) combine a broad research and education approach to revolutionize two major fundamental components of energy conversion and energy efficiency in solid-state electronics and optoelectronics: (a) to drastically improve the energy efficiency and energy conversion figure-of-merits by developing novel heterostructure based materials, metamaterials and active device components, and (b) to understand and innovate physical principles, and engineer materials for efficient heat, light and current transports. These research objectives are broadly categorized in three research themes. Sub-categories are described in details.