CAREER: Opto- Thermo- Electronic Devices

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

The ability to change and control precisely material properties of semiconductors by several orders of magnitude has revolutionized our information age. While the research in semiconductor devices in the last 40 years has been concentrated on the optimization and control of the opto-electronic properties, there has only been a limited work on thermo-electric properties. In this research program, we propose to use same techniques of bandgap engineering and thin film epitaxy to improve the thermal characteristics and design novel high performance optoelectronic components. The core of proposed research is based on the fact that semiconductor heterostructures and superlattices can modify the average transport energy of electrons beyond what can be achieved using bulk material. Such modifications in conjunction with judicious choice of device parameters can make the electron gas absorb thermal energy from one area in the device and deposit it in another area near a heat sink. The integrated electrical, optical and thermal approach gives the opportunity to improve the performance of existing devices. As specific examples, we will study the design of light emitting diodes and high power semiconductor lasers in which the device performance is least affected by ambient temperature changes. This research will be integrated in an undergraduate class on Properties of Materials. In this class, students will perform simple transport measurements such as heat conduction, Hall or Peltier effect. Through the graphical representation of the transport equation developed for the research part of this proposal, students will be able to see how the electron gas is moving through the semiconductor, why there is Wiedemann-Franz law, and how passage from one semiconductor to another one gives rise to Peltier effect.