Prof. Rui Q. Yang is the inventor of Interband Cascade Lasers (ICLs) and has made significant contributions to the development of ICLs and the related applications. At OU, our group has been working on it since 2007. We demonstrated high-performance InAs-based Plasmon-waveguide ICLs and expanded the emission wavelength to ~10.4um, which is the longest wavelength achieved among III-V interband lasers. The IC lasers that he invented and developed with his colleagues at JPL have been selected for NASA flight mission to Mars, one of which is currently working on Curiosity Mars rover.
Interband Cascade IR Photodetectors (ICIPs) utilize a discrete absorber architecture,where individual absorbers are sandwiched between quantum engineered electron and hole barriers to form a series of interband cascade stages. As such, photogenerated carriers travel only over one cascade stage before they recombine in the next stage, and every individual cascade stage can be significantly shorter than the diffusion length, while the total thickness of all the absorbers can be comparable or even longer than the diffusion length. Hence, the discrete architecture of ICIPs provides a great deal of flexibility for quantum engineering cascade stages and manipulating carrier transport to achieve high temperature and high speed operation without compromising the absorption quantum efficiency. Furthermore, adding extra stages will lower the noise current, which roughly scales inversely with the square root of the total number of stages.
Interband Cascade Phtovoltaic (PV) Devices are like IC lasers running backward. Each of the absorbers is made from the same constituent materials. In this type of PV devices, it is easy to adjust the absorption wavelengths to optimize the slicing of the incident photon flux vs. energy spectrum.
Features of IC Infrared PV devices:
- Multiple stages with the same energy gap can be used to absorb all the photons in a particular portion of the source spectrum while increasing the open-circuit voltage (especially good with concentrators)
- High-voltage, low current characteristic of the multi-stage ICPV device will reduce losses.
- Interband tunneling regions with type-II heterostructures will be less resistive than Esaki tunnel p-n junctions
- Minimize the losses associated with residual parasitic device resistances
- Sb-based material system is adequate from near- to mid-IR regions
- Thermophotovoltaic (TPV) cells for applications such as waste heat recovery.
