In thin-film light-emitting diodes (LEDs) absorption of the generated light in the substrate is avoided by the transfer of the epitaxial LED layers on a reflecting carrier. The extraction efficiency can be further enhanced by texturing the top surface. We developed a structure for high-efficiency surface-textured thin-film AlGaInP LEDs with improved heat dissipation by wafer-bonding onto a carrier substrate using conductive epoxy. The improved heat removal toward the substrate through the conductive epoxy increases the maximum allowable current density by more than a factor of two, compared to LEDs bonded on the carrier substrate with benzocyclobutene. As a result, an optical power of 65 mW is achieved for unencapsulated devices emitting at 650 nm. Using this technology, we also demonstrate an external quantum efficiency of 43% for unencapsulated LEDs at a peak wavelength of 650 nm, which is the highest reported efficiency for AlGaInP thin-film LEDs. The external quantum efficiency increases to 52% at 100 K
Rooman, C, Kuijk, M, De Jonge, S, Karnutsch, C, Butendeich, R, Streubel, K & Heremans, P 2005, 'High-efficiency AlGaInP thin-film LEDs using surface texturing and waferbonding with conductive epoxy', IEEE Photonics Technology Letters, vol. 17, no. 12, pp. 2649-2651.
Rooman, C., Kuijk, M., De Jonge, S., Karnutsch, C., Butendeich, R., Streubel, K., & Heremans, P. (2005). High-efficiency AlGaInP thin-film LEDs using surface texturing and waferbonding with conductive epoxy. IEEE Photonics Technology Letters, 17(12), 2649-2651.
@article{18d31bdf6b7341dbb6544876bcad446f,
title = "High-efficiency AlGaInP thin-film LEDs using surface texturing and waferbonding with conductive epoxy",
abstract = "In thin-film light-emitting diodes (LEDs) absorption of the generated light in the substrate is avoided by the transfer of the epitaxial LED layers on a reflecting carrier. The extraction efficiency can be further enhanced by texturing the top surface. We developed a structure for high-efficiency surface-textured thin-film AlGaInP LEDs with improved heat dissipation by wafer-bonding onto a carrier substrate using conductive epoxy. The improved heat removal toward the substrate through the conductive epoxy increases the maximum allowable current density by more than a factor of two, compared to LEDs bonded on the carrier substrate with benzocyclobutene. As a result, an optical power of 65 mW is achieved for unencapsulated devices emitting at 650 nm. Using this technology, we also demonstrate an external quantum efficiency of 43% for unencapsulated LEDs at a peak wavelength of 650 nm, which is the highest reported efficiency for AlGaInP thin-film LEDs. The external quantum efficiency increases to 52% at 100 K",
keywords = "AlGaInP, conductive epoxy, high-efficiency, light-emitting diodes (LEDs)",
author = "Cathleen Rooman and Maarten Kuijk and {De Jonge}, Stijn and C. Karnutsch and R. Butendeich and K. Streubel and P. Heremans",
note = "Photon. Technol. Lett, Vol. 17, Nr. 12, pp. 2649-2651, , , , , , , , , , , , , , , , , , , , IEEE.",
year = "2005",
month = dec,
day = "1",
language = "English",
volume = "17",
pages = "2649--2651",
journal = "IEEE Photonics Technology Letters",
issn = "1041-1135",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "12",
}