Popis: |
Polarized electroluminescence (EL) from m-plane InGaN-based blue light emitting diodes (LEDs) has been investigated. These LEDs comprised a ZnO transparent electrode as an anode, polished mirror-like sidewalls, and a polished backside with the reflective mirror to remove the light scattering due to the surface roughness. The polarization ratio at room temperature was 0.80, which was relatively high compared to known values and was considered to be close to the true value. The reduction of the light scattering is essential for the accurate measurement of the polarized emission. The EL spectra from different three planes, i.e., m-, c-, and a-planes, have been measured. The peak energies of spectra polarized parallel to m-plane, emitted from a- and c-plane sidewalls, agree with the values of the two components emitted from top m-plane surface. The strongest component was E⊥c while the second strongest was E∥c. The E∥m component was extremely low compared with E∥c. |