The objective of this program is to develop mid-infrared photodetectors using indium phosphide-based materials for applications where high sensitivity and near-room temperature operation are desired. These materials provides advantages including the use of compressive and tensile strained materials for flexible device design options and mature wafer foundry capabilities for processing InP-based structures. This program is transformative in that it couples mid-infrared optoelectronics to a technology platform that has been well developed in industry but does not currently allow use of this wavelength range.
The intellectual merit is to use a resonant-cavity approach that combines a thin, strained quantum well absorption region with high-reflectivity mirrors. Experiments have shown that these quantum wells can absorb light beyond 3000 nm at room temperature. The addition of strain with a novel strain compensation approach will allow an extension of the detection wavelength. The use of a resonant cavity decouples the optical absorption length and physical thicknesses of the quantum wells leading to both higher quantum efficiency and lower dark currents.
The broader impacts of this program are to create a technology that can have a positive influence on society through its use in both military and civilian applications. In addition, this program focuses on two main categories for research/education integration: recruiting a talented undergraduate to pursue research with the goal of encouraging him or her to pursue graduate studies and the development of educational materials which can be used to educate first-year engineering students on the societal benefits of this research.
