Bengi, A.Lisesivdin, S.B.Kasap, M.Mammadov, T.Ozcelik, S.Özbay, Ekmel2016-02-082016-02-08201013698001http://hdl.handle.net/11693/22374The 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.English2DEGAlGaN/GaNMOCVDPhotoluminescenceUnder biasAlGaN/GaNAlGaN/GaN heterostructuresApplied electric fieldBandbendingEmission bandsExciton transitionsHall measurementsHetero interfacesLuminescence intensityMetalorganic chemical vapor depositionMOCVDNear band edgePhotoluminescence measurementsPL measurementsRadiative lifetimeRoom temperatureTwo-dimensional electron gas (2DEG)Ultraviolet luminescenceYellow bandsYellow luminescence bandsCrystalsElectric field measurementElectric fieldsElectron gasMetallorganic chemical vapor depositionOptical transitionsPhotoluminescenceTwo dimensional electron gasGallium nitrideArticle10.1016/j.mssp.2010.05.004