Supplying the world with energy in a sustainable manner is one of the most pressing issues in modern society. Dramatically improved control over heat, electricity and solar energy is essential to create a new energy paradigm. Our program explores the energy conversion and storage using 1) nanomaterials along several different paths: 2) Solar Energy, 3) Energy Storage, 4) Heat Management and Conversion. Leveraging the unique properties of nanomaterials, this program seeks significant advancements in the basic understanding of materials and mechanisms, as well as revolutionary breakthroughs in designs and processes.
Nanomaterials:
Nanomaterials with carefully tailored properties (composition, size, interface, geometry, structure) can be used to manipulate the flow of phonons, electrons and photons, to enable novel energy devices in an unconventional manner.
The twin pillars of nanomaterials offer great opportunities. On the one hand, each individual nanostructure is intrinsically a small, clean system, facilitating fundamental study such as dislocation dynamics at low dimensional materials. On the other hand, the unique properties of nanomaterials, arising from their size and geometry, enable the unprecedented ability to manipulate flows of electrons, photons, ions, and phonons, thereby creating vast opportunities for structure and process innovations.
Solar Energy:
The solar energy that reaches the earth in one hour is enough to supply the energy needs of the earth for a year. However, to make solar energy significant portion of the future energy portfolio, the key will be the development of devices and systems that can efficiently and cost-effectively harness, convert and store solar energy.
Nanoscale photon management, enabling efficient absorption within very thin absorbers through light trapping, is critical to all solar energy devices, as it can improve the efficiency by minimizing optical and electrical losses, and cut cost by relaxing material quality and reducing material usage, process time and capital investment. Our work is one of the earliest that apply nanoscale photon management into solar cells.
Heat Management and Conversion:
Heat flow control is essential for broad applications of heating, cooling and energy conversion. Like power electronic devices developed for the control of electric power, it is very desirable to develop advanced all-thermal devices to self-control the heat flow without consuming other forms of energy.
Nanomaterials with well-defined size, geometry and interface can be used to control phonon behavior, therefore the heat flow in an unprecedented manner.
Energy Storage:
Even though lithium (Li) ion batteries represent major and expanding energy solutions, significant improvement are still needed in order to play a more substantial role in portable electronics and future electric vehicles. On one hand, several key issues such as material fracture, Li dendrite growth and formation of solid electrolyte interphase on Li are still the subjects of much controversy. On the other hand, the dramatic boost in energy density and lifetime is still needed for applications like mobile devices. With the interplay of advanced material characterization tool, structure design and process development, our program focus on both fundamental understanding and improving energy density and cycle life of batteries.