Photocapacitance and excitation photocapacitance methods were applied to reveal the dislocation-induced deep levels in coalescent epitaxial lateral overgrowth layers of InP. Point-contact Schottky barrier junctions with small junction areas were formed on dislocated and dislocation-free regions by using wedge wire-bonding of Au, and photocapacitance measurements were then carried out at 30 K. In the dislocation-free layers, the dominant deep level was located at 1.30 eV below the conduction band, whereas in the dislocated area, dominant deep levels were detected at 0.86 eV (λ=1.44 μm) and 1.05 eV (λ=1.18 μm) below the conduction band. A neutralized state was also detected at 0.66 eV above the valence band. From the detailed excitation photocapacitance results, it is shown that the defect configuration coordinate diagram of the dislocation-induced deep levels was considered with large Frank-Condon shifts (dFC) of 0.28 eV. This means that the atomic configurations around the deep levels are highly relaxed, as expected from the structures of the dislocation cores.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2006 Dec 18|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics