FAR FIELD MEASUREMENTS OF PhC LED PREPARED BY E–BEAM LITHOGRAPHY
Pavol Hronec – Jaroslava Škriniarová – Anna Benčurová – Pavol Nemec
– Dušan Pudiš – Jaroslav Kováč
The paper deals with optical characterization of the Al0.295Ga0.705As/GaAs multi-quantum well light emitting diode (LED) structure with photonic crystal (2D PhC) patterned on the top of the structure using Electron Beam Direct Write Lithography (EBDWL). Light-current characteristics measured by integrating sphere shows increase of extracted light intensity as 21.1 %. Additionally, extracted light intensity was studied by far-field measurements as a complementary method to light-current characteristics. The far-field measurements show increase of extracted light intensity as 31.2 %. We suggest this method as more suitable for evaluation of extracted light intensity because it omits emission from edges of the LED and thus light is measured only from the area where PhC is patterned.
Keywords: LED, Electron beam direct write lithography, photonic crystal, far field, light extraction