Dandan Zhu, B. Corbett, B. Roycroft, P. Maaskant, C. McAleese, M. Akhter, M. Kappers, C. Humphreys
{"title":"Enhanced efficiency of near-UV emitting LEDs for solid state lighting applications","authors":"Dandan Zhu, B. Corbett, B. Roycroft, P. Maaskant, C. McAleese, M. Akhter, M. Kappers, C. Humphreys","doi":"10.1117/12.758799","DOIUrl":null,"url":null,"abstract":"The performance of a series of near-UV (~385 nm) emitting LEDs, consisting of high efficiency InGaN/AlInGaN QWs in the active region, was investigated. Significantly reduced roll-over of efficiency at high current density was found compared to InGaN/GaN LEDs emitting at a similar wavelength. The importance of optical cavity effects in flip-chip geometry devices has also been investigated. The light output was enhanced by more than a factor of 2 when the light-emitting region was located at an anti-node position with respect to a high reflectivity current injection mirror. A power of 0.49 mW into a numerical aperture of 0.5 was obtained for a junction area of 50 micrometers in diameter and a current of 30 mA, corresponding to a radiance of 30 W/cm2/str.","PeriodicalId":245823,"journal":{"name":"Manufacturing LEDs for Lighting and Display","volume":"82 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2007-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Manufacturing LEDs for Lighting and Display","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1117/12.758799","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The performance of a series of near-UV (~385 nm) emitting LEDs, consisting of high efficiency InGaN/AlInGaN QWs in the active region, was investigated. Significantly reduced roll-over of efficiency at high current density was found compared to InGaN/GaN LEDs emitting at a similar wavelength. The importance of optical cavity effects in flip-chip geometry devices has also been investigated. The light output was enhanced by more than a factor of 2 when the light-emitting region was located at an anti-node position with respect to a high reflectivity current injection mirror. A power of 0.49 mW into a numerical aperture of 0.5 was obtained for a junction area of 50 micrometers in diameter and a current of 30 mA, corresponding to a radiance of 30 W/cm2/str.