Study of Defects in GaN In Situ Doped with Eu3+ Ion Grown by OMVPE
Abstract
In this work, GaN epilayer in situ doped with Eu3+ ions was deposited on the top of an undoped n-GaN/LT-GaN/sapphire structure by organometallic vapor-phase epitaxy. A set of different ohmic and Schottky contacts on GaN:Eu3+ surface was fabricated by electron-beam evaporation for performing deep level transient spectroscopy (DLTS) measurement. The deep defect energy levels in GaN:Eu3+ epilayer were assessed by standard DLTS and high resolution Laplace DLTS (L-DLTS). Three dominant DLTS peaks were observed in the temperature range from 35 K to 400 K. The calculated activation energies of these defect energy levels were 0.108 ± 0.03 eV (Trap A), 0.287 ± 0.04 eV (Trap B) and 0.485 ± 0.06 eV (Trap C) below conduction band edge, respectively. High resolution L-DLTS conducted for the GaN:Eu3+ epilayer revealed at least four closely spaced defect energy levels associated with Trap B. It is proposed that these defect energy levels correspond to the selected optically active Eu3+ ion centers in GaN host previously identified by optical studies in this material (Fujiwara and Dierolf in Jpn J Appl Phys 53:05FA13, 2014).
- Publication:
-
Journal of Electronic Materials
- Pub Date:
- April 2016
- DOI:
- 10.1007/s11664-016-4337-4
- Bibcode:
- 2016JEMat..45.2001W
- Keywords:
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- Deep level transient spectroscopy (DLTS);
- laplace deep level transient spectroscopy (L-DLTS);
- europium ions;
- GaN