B2.

Project title: Modeling of Semiconductor Quantum Well Devices for Optoelectronics Applications

The advance of semiconductor growth techniques, such as molecular beam epitaxy (MBE) and metal organic chemical vapour deposition (MOCVD), enables the grow th of thin layers (down to 10? of high quality semiconductor materials and therefore permits the construction of lattice matched (e.g. AlGaAs/GaAs) or slightly mismatched (e.g. InGaAs/GaAs) heterostructures known as quantum wells (QWs). These QWs give new physical mechanisms that can be engineered at the atomic level to give new devices. In optics and optoelectronics, QWs enable the fabrication of low-energy, high-speed optical modulators and switches. A very important aspect of these devices is that they are compatible with existing optical (such as waveguides, modulators, and diode lasers) and electronic devices, thereby enabling optoelectronic integrated circuit. The optical properties of quantum wells, in particular their complex refractive index and absorption coefficients, are important for the design of integrated optoelectronic devices such as waveguides, modulators and lasers. However, the values of these optical parameters are not accurately known which are required for different quantum well structures in order to fabricate devices with an optimal operating performance for the design of optoelectronic integrated circuits. The project will study these optical properties for the different quantum wells and also predict optimal optical parameters for optoelectronic device design.

Supervisors: Prof K S Chan (apkschan@cityu.edu.hk)

Suitable for: M.Phil. or Ph.D.