Flexibility properties of type-Ⅱ InAs/GaSb SL to design MWIR pin photodiodes

摘要

InAs/GaSb superlattice (SL) is a peculiar quantum system for infrared detection, where electrical and optical properties are directly governed by the composition and the periodicity of the InAs/GaSb cell. Indeed, several structures with different InAs to GaSb thickness ratios in each SL period, can target the same cut-off wavelength. Likewise, the type of conductivity of the non-intentionally doped SL structure is also linked to the InAs/GaSb SL period. The objective of this communication is to use the flexibility properties of InAs/GaSb SL to design and then to fabricate by MBE a pin photodiode where the active zone is made of different SL periods. Electrical and electro-optical characterizations are reported. The results show that SL structure for the MWIR domain can be designed by combining the best of each SL periods.