Analysis of defect related optical transitions in biased AlGaN/GaN heterostructures
Author
Bengi, A.
Lisesivdin, S.B.
Kasap, M.
Mammadov, T.
Ozcelik, S.
Özbay, Ekmel
Date
2010Source Title
Materials Science in Semiconductor Processing
Print ISSN
13698001
Volume
13
Issue
2
Pages
105 - 108
Language
English
Type
ArticleItem Usage Stats
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Abstract
The optical transitions in AlGaN/GaN heterostructures that are grown by metalorganic chemical vapor deposition (MOCVD) have been investigated in detail by using Hall and room temperature (RT) photoluminescence (PL) measurements. The Hall measurements show that there is two-dimensional electron gas (2DEG) conduction at the AlGaN/GaN heterointerface. PL measurements show that in addition to the characteristic near-band edge (BE) transition, there are blue (BL) and yellow luminescence (YL) bands, free-exciton transition (FE), and a neighboring emission band (NEB). To analyze these transitions in detail, the PL measurements were taken under bias where the applied electric field changed from 0 to 50 V/cm. Due to the applied electric field, band bending occurs and NEB separates into two different peaks as an ultraviolet luminescence (UVL) and Y4 band. Among these bands, only the yellow band is unaffected with the applied electric field. The luminescence intensity change of these bands with an electric field is investigated in detail. As a result, the most probable candidate of the intensity decrease with an increasing electric field is the reduction in the radiative lifetime. © 2010 Elsevier Ltd. All rights reserved.
Keywords
2DEGAlGaN/GaN
MOCVD
Photoluminescence
Under bias
AlGaN/GaN
AlGaN/GaN heterostructures
Applied electric field
Bandbending
Emission bands
Exciton transitions
Hall measurements
Hetero interfaces
Luminescence intensity
Metalorganic chemical vapor deposition
MOCVD
Near band edge
Photoluminescence measurements
PL measurements
Radiative lifetime
Room temperature
Two-dimensional electron gas (2DEG)
Ultraviolet luminescence
Yellow bands
Yellow luminescence bands
Crystals
Electric field measurement
Electric fields
Electron gas
Metallorganic chemical vapor deposition
Optical transitions
Photoluminescence
Two dimensional electron gas
Gallium nitride