Light emission between 2 and 4 µm: Innovative active region designs for InP- and GaSb-based devices

This work shows different approaches to cover the spectral range from 2 to 4 μm with active regions based on InP and GaSb for devices suitable as light sources for gas-sensing applications. For shorter wavelengths up to 2.3 μm type-I InP-based quantum wells with rectangular and triangular shape are the preferred choice, beyond that GaSb-based type-I active regions were studied to cover the wavelengths up to 4 μm. An alternative method is implementing type-II structures on InP to exploit the advantages of this well-known material system for device fabrication. For the different methods device designs, growth issues and applications will be discussed.