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<title>Size dependence of record-efficiency non-resonant cavity light-emitting diodes</title>

1999; SPIE; Volume: 3621; Linguagem: Inglês

10.1117/12.344480

1996-756X

Reiner Windisch, Paul Heremans, B. Dutta, Štefan Németh, A. Knobloch, Gottfried H. Doehler, Gustaaf Borghs,

Semiconductor Quantum Structures and Devices

Non-resonant cavity light-emitting diodes (NRC-LED's) are based on the combination of surface texturing and the application of a back mirror. With this concept, the extraction efficiency of LED's can be enhanced considerably. We fabricated NRC-LED's with a more sophisticated design employing an oxidized current aperture, which is similar to the commonly used for vertical-cavity surface-emitting lasers. In our NRC-LED's, it confines the injection current to the center of the device in order to reduce light generation below the top contact. We analyze the impact of the aperture size on the device performance, and we show that both the maximum efficiency and the injection current where it is reached are strongly dependent on the device size. Its correlation with the temperature in the active region and the current density is discussed. In addition, we demonstrate that a considerably fraction of the light can be extracted from lateral guided modes in the LED structure by extending the surface texturing beyond the device mesa. Devices fabricated by applying all of the above techniques result in record external quantum efficiencies of 31%.