Green (In,Ga,Al)P-GaP light-emitting diodes grown on high-index GaAs surfaces
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Yksityiskohdat
Alkuperäiskieli | Englanti |
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Otsikko | Proceedings of SPIE |
Alaotsikko | Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XIX |
Kustantaja | SPIE |
Vuosikerta | 9383 |
ISBN (painettu) | 9781628414738 |
DOI - pysyväislinkit | |
Tila | Julkaistu - 2015 |
OKM-julkaisutyyppi | A4 Artikkeli konferenssijulkaisussa |
Tapahtuma | Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XIX - San Francisco, Yhdysvallat Kesto: 10 helmikuuta 2015 → 12 helmikuuta 2015 |
Conference
Conference | Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XIX |
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Maa | Yhdysvallat |
Kaupunki | San Francisco |
Ajanjakso | 10/02/15 → 12/02/15 |
Tiivistelmä
We report on green (550-560 nm) electroluminescence (EL) from (Al<inf>0.5</inf>Ga<inf>0.5</inf>)<inf>0.5</inf>In<inf>0.5</inf>P-(Al<inf>0.8</inf>Ga<inf>0.2</inf>)<inf>0.5</inf>In<inf>0.5</inf>P double p-i-n heterostructures with monolayer-scale tensile strained GaP insertions in the cladding layers and light-emitting diodes (LEDs) based thereupon. The structures are grown side-by-side on high-index and (100) GaAs substrates by molecular beam epitaxy. Cross-sectional transmission electron microscopy studies indicate that GaP insertions are flat, thus the GaP-barrier substrate orientation-dependent heights should match the predictions of the flat model. At moderate current densities (∼500 A/cm<sup>2</sup>) the EL intensity of the structures is comparable for all substrate orientations. Opposite to the (100)-grown strictures, the EL spectra of (211) and (311)-grown devices are shifted towards shorter wavelengths (∼550 nm at room temperature). At high current densities (>1 kA/cm<sup>2</sup>) a much higher EL intensity is achieved for the devices grown on high-index substrates. The integrated intensity of (311)-grown structures gradually saturates at current densities above 4 kA/cm<sup>2</sup>, whereas no saturation is revealed for (211)-grown structures up to the current densities above 14 kA/cm<sup>2</sup>. We attribute the effect to the surface orientation-dependent engineering of the GaP band structure which prevents the escape of the nonequilibrium electrons into the indirect conduction band minima of the p- doped (Al<inf>0.8</inf>Ga<inf>0.2</inf>)<inf>0.5</inf>In<inf>0.5</inf>P cladding layers.