Development of Experimental System for Ultra-Fast UV-Visible Spectroscopy of Wide-Band-Gap Semiconductors

Rensselaer Polytechnic Institute, Troy NY

Investigators

Abstract

We recently proposed and demonstrated novel Strain Energy Band Engineering (SEBE) in AlInGaN-based quantum wells and multiple quantum well structures. SEBE will allow us to independently control energy band offset and lattice mismatch (strain) in AlInGaN-based heterostructures. This should allow us to develop a new generation of electronic and photonic devices, since we should be able to obtain a new family of heterostructures with controlled properties. To achieve this goal, we must develop a high power nonlinear visible/UV spectroscopy system in order to study built-in electric fields, non-equilibrium hot carrier dynamics and optical gain in wide band gap semiconductors and heterostructures under strongly non-equilibrium conditions. This system will allow us to apply our experience with wide-band gap electronic and optoelectronic materials and devices to a new, and even more exciting area of photonic wide band gap materials and devices with possible application to solid-state lighting, which is 10 times more efficient than standard incandescent lighting. We will take advantage of being the only group in the world that has access to bulk AlN, bulk GaN, and one of the best sources of epitaxial binary, ternary, and quaternary wide band gap films. We need the system that allows us to obtain (i) subpicosecond time resolution, (ii) that is tunable in the range from 200 nm to 800 nm (to cover the AlN-GaN-InN materials system), (iii) operational in the temperature range from 4.2 K to 300K.