Metasurface-integrated semipolar (202¯1) In _<i>x</i> Ga _{1− <i>x</i>} N quantum wells towards efficient circularly-polarized LEDs

In recent years, circularly polarized (CP) light-emitting diode (LED) has attracted considerable attention for next-generation display and bio-imaging applications. Particularly, an integrable single-chip CP emitter instead of a conventional large optical setup with a linear polarizer and a quarter-wave plate has been intensively studied to realize high-resolution devices. Herein, we demonstrate a CP light emitter consisting of a semipolar (202¯1) In x Ga 1− x N quantum wells with stripe-shaped SiN x metasurface. Partially linearly-polarized light from the semipolar In x Ga 1− x N quantum wells was converted to CP-light through the metasurface with a polarization-conversion ratio of 68%. We experimentally confirm a clear CP-emission at room temperature under an optical excitation, and the circular polarization degree reaches 0.27 at the peak wavelength of 408 nm. These results indicate that In x Ga 1− x N-based CP-LEDs open new avenues for the development of next-generation optical applications.