Cathode-luminescence study of photonic crystal green InxGa1-xN/InyGa1-yN light emitting diodes

Abstract

We report on the enhancement of cathode-luminescence in InxGa1-xN/InyGa1-yN green light emitting diode structure using two-dimensional photonic crystal. The square lattice arrays of photonic crystals with nominal diameter/periodicity of 200/500 nm were fabricated by electron beam lithography. Inductively coupled plasma dry etching was used to etch and define photonic crystals. Three samples with different etch depths, i.e., 175, 95. and 65 am, were fabricated and studied. Field emission scanning electron microscope analysis shows that air holes of photonic crystal structure With truncated-inverted-cone shapes were fabricated after dry etching. Cathode-luminescence measurements showed that up to about 28-fold enhancement Of luminescence intensity has been obtained at room temperature. Spatially resolved luminescence profile around the single hole, which composes photonic crystal structure, was also obtained by cathode-luminescence measurements. (C) 2008 Elsevier B.V. All rights reserved