Article ID Journal Published Year Pages File Type
7839688 Journal of Luminescence 2018 6 Pages PDF
Abstract
A conventional planar InGaN/GaN multiple quantum well (MQW)-based light emitting diode (LED) producing a blue-green dual-wavelength spectrum, due to phase separation in the InGaN well layers, is grown, and fabricated into a nanopillar (NP) LED array structure with an etching depth penetrating through the MQW region using a top-down dry etching process. Excitation power and temperature dependences of the photoluminescence (PL) spectra of the planar and NP samples have shown that the fabrication of the nanotexture not only decreases the quantum-confined Stark effect (QCSE), but also enhances the carrier localisation effect, both in the InGaN matrix region and in the In-rich quasi-quantum dot (QD) region, due to the reduction of the strain relaxation-induced piezoelectric field in the MQWs embedded in the nanopillars. Moreover, the fabrication of the nanotexture also improves the light extraction efficiency (LEE), due to the increased light-extracting surface area and light-guiding effect. These results are also consistent with the measured quantum efficiencies of the two samples.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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