Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1547963 | Physica E: Low-dimensional Systems and Nanostructures | 2006 | 4 Pages |
Abstract
Photoreflectance (PR) and photoluminescence (PL) spectra are measured for a series of In0.54Ga0.46P1âyNy/GaAs heterostructures at temperatures ranging from 25 to 300Â K. The redshifts of the PR and PL peaks indicate that the band gap of InGaPN is dramatically reduced as nitrogen is incorporated. The transition energies of the band edge at various temperatures are measured and least-squares fitted to the Varshni equation. With N incorporation, the PL peak energy exhibits a particular behavior with temperature, which is not observed in PR spectra. This is attributed to carrier localization at low temperatures resulting from N clusters in the samples. In addition, the emergence of additional peaks in PR spectra as N is incorporated implies that the band alignment switches from type I to type II, due to the lowering of the conduction band, thus forming a two-dimensional electron gas (2DEG) in the interface region between InGaPN and GaAs. The number of confined levels in the 2DEG is found to increase with N concentrations.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
K.I. Lin, K.C. Chen, T.S. Wang, Y.T. Lu, J.S. Hwang,