Investigation of narrow-band thermal emission from intersubband transitions in quantum wells.

We investigate thermal emission from n-doped GaAs/AlGaAs quantum wells (QWs). Emission peaks with Lorentzian shapes (linewidth 11~19 meV) that reflect transitions between the first and second conduction subbands are observed in the mid-infrared range. It is demonstrated that the emission characteristics can be tuned by modifying the QW parameters. The peak emissivity is increased from 0.3 to 0.9 by modifying the doping density, and the peak wavelength is tuned from 6 to 10 μm by changing the well width. The obtained results are useful for the design of narrow-band thermal emitters. [ABSTRACT FROM AUTHOR]