MBE systems traditionally relied upon ultra-pure solid elements, such as gallium and arsenic, which could only be used to grow arsenides, leaving out other compounds that are important in fiber-optic communications.
When Tu came to UCSD in 1988, he set up one of the first gas-source MBE systems in the United States, enabling his research team to grow a wider variety of materials -- including arsenides, phosphides, nitrides, and mixtures of them – than was previously possible. Currently, Tu is growing dilute nitrides – a new class of materials pioneered in his shop over the past 12 years – for intermediate-band solar cells and nanowire solar cells.
The MBE Innovator Award recognizes individuals whose innovative work has significantly advanced the field of MBE in materials research, device development or commercialization, or equipment development.