Optical polarization of light emission from sidewalls of single quantum well near interface in spontaneous regime

Abstract Color conversion is necessary in the case of blue light emitting diodes (LEDs) in the field of display applications. One of the most common strategies consists of colloidal emitter quantum dots (QDs) pumped by a GaN based LED. To improve the coupling between the active LED area and the QDs, the authors investigated the particular case of the near field coupling by placing the LED quantum wells (QWs) near its surface. This coupling strongly depends on the dipole orientation. We report results on the polarized light emission from the sidewall of an LED. More precisely, we studied a single QW InGaN structure, located at a few nanometers from the LED’s surface. Dies were placed under a confocal microscope with the sidewall perpendicular to the optical axis. A rotational polarizer was used to analyze the emitted light. This experiment allows determining the polarization of the spontaneous emission. Experimental results demonstrate the strong impact of the surface proximity on the polarization of emitted light.