Efficiency Improvement of 630 nm AlGaInP Light-Emitting Diodes based on AlGaAs Bottom Window

Metal organic chemical vapor deposition (MOCVD) based aluminum gallium arsenide (AlGaAs) used as the bottom window (BW), which was inserted between the light-emitting diode (LED) structure and the absorbing substrate, has been proposed to improve the extraction efficiency of 630 nm AlGaInP LEDs. In...

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Published inJapanese Journal of Applied Physics Vol. 52; no. 10; pp. 102101 - 102101-4
Main Authors Lee, Hyung Joo, Kim, Young Jin, Kim, Seong Un, Jo, Ju Ung, Lee, Choong Hun, Kim, Jae Hoon, Ahn, Su Chang
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.10.2013
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Summary:Metal organic chemical vapor deposition (MOCVD) based aluminum gallium arsenide (AlGaAs) used as the bottom window (BW), which was inserted between the light-emitting diode (LED) structure and the absorbing substrate, has been proposed to improve the extraction efficiency of 630 nm AlGaInP LEDs. In an AlGaInP LED with this AlGaAs BW, enhanced light extraction efficiency was observed, as some of the light emitted from the active region to the absorbing substrate could pass out of the LED through the BW. In addition, it was found that a output power of 8 mW was obtained from an AlGaInP LED with both a BW and a distribution Bragg reflector (DBR), a nearly two fold improvement of over 4.2 mW that was obtained from a conventional one at an injection current of 80 mA.
Bibliography:(Color online) SEM images (upper panels) and schematics (lower panels) of structures of (a) conventional AlGaInP LED and AlGaInP LEDs with (b) BW only, (c) DBR only, and (d) both BW and DBR. (Color online) Photoluminescence measurements of AlGaInP LEDs having different structures. (Color online) Light-emitting paths for (a) conventional AlGaInP LED chip and AlGaInP LED chips with (b) BW only and (c) both BW and DBR. (Color online) Comparison of the $L$--$I$--$V$ characteristic curves of conventional AlGaInP LED chip and AlGaInP LED chips with BW only, DBR only, and both BW and DBR.
ISSN:0021-4922
1347-4065
DOI:10.7567/JJAP.52.102101