  The enhancement of the power conversion efficiency (PCE), and subsequent
reduction of cost, of light emitting diodes (LEDs) is of crucial importance in
the current lightening market. For this reason, we propose here a PCE-enhanced
LED architecture, based on a partially reflecting metasurface cavity (PRMC)
structure. This structure simultaneously enhances the light extraction
efficiency (LEE) and the spontaneous emission rate (SER) of the LED by
enforcing the emitted light to radiate perpendicularly to the device, so as to
suppress wave trapping and enhance field confinement near the emitter, while
ensuring cavity resonance matching and maximal constructive field interference.
The PRMC structure is designed using a recent surface susceptibility
metasurface synthesis technique. A PRMC blue LED design is presented and
demonstrated by full-wave simulation to provide LEE and SER enhancements by
factors 4.0 and 1.9, respectively, which correspond to PCE enhancement factors
of 6.2, 5.2 and 4.5 for IQEs of 0.25, 0.5 and 0.75, respectively, suggesting
that the PRMC concept has a promising potential in LED technology.
