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RESEARCH PRODUCT
Luminescence and electron transport properties of GaN and AlN layers
J. JansonsAndris GulansH. StolzT. BarfelsH.-j. FittingMaris SpringisA. VeispalsI. Talesubject
Electron mobilityRadiationPhotoluminescenceMaterials scienceScanning electron microscopebusiness.industryExcitonCathodoluminescenceMolecular physicsSapphireOptoelectronicsCharge carrierLuminescencebusinessInstrumentationdescription
Abstract The transport properties of free charge carriers, photo- and cathodo-luminescence (CV) in GaN and AlN films obtained by MOCVD technique on sapphire and Si substrates, are investigated. The concentration of free charge carriers in GaN is of order 10 17 – 10 19 cm −3 whereas AlN thin films are insulating. The Hall mobility of electrons are 80– 140 cm 2 / V s ). In undoped GaN films the spectral composition of CL is close to photoluminescence (PL) when excited in the region of band–band transitions. The decay time constant of the 3.44 eV UV emission attributed to the bound exciton is considerably less than 1 ns , whereas the 3.26 eV violet (VI) band shows a slow hyperbolical decay over about 1 μs . The known yellow band appears at 2.25 eV due to transitions via localised states. In AlN the spectral composition of the broad CL band is close to that from bulk materials attributed to charge transfer transitions in deep oxygen-related donor–acceptor centres.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2001-10-01 | Radiation Measurements |