Semiconductor quantum plasmons for high frequency thermal emission

TL;DR

This paper demonstrates that heavily doped semiconductor layers can support volume plasmons capable of high-frequency thermal emission, with potential applications in infrared and microwave technologies.

Contribution

It shows that volume plasmons can form in doped semiconductor layers without potential barriers and can be modulated for high-frequency thermal emission.

Findings

Incandescent emission measured up to 50 MHz

Theoretical model predicts emission cutoff in tens of GHz

Device fabrication confirms plasmon-based thermal emission

Abstract

Plasmons in heavily doped semiconductor layers are optically active excitations with sharp resonances in the 5-15 um wavelength region set by the doping level and the effective mass. Here we demonstrate that volume plasmons can form in doped layers of widths of hundreds of nanometers, without the need of potential barrier for electronic confinement. Their strong interaction with light makes them perfect absorber and therefore suitable for incandescent emission. Moreover, by injecting microwave current in the doped layer, we can modulate the temperature of the electron gas. We have fabricated devices for high frequency thermal emission and measured incandescent emission up to 50MHz, limited by the cutoff of our detector. The frequency dependent thermal emission is very well reproduced by our theoretical model that let us envision a frequency cutoff in the tens of GHz.