High responsivity A-plane GaN-based metal-semiconductor-metal photodetectors for polarization-sensitive applications

Navarro, A.
Rivera, C.
Pereiro, J.
Munoz, E.
İmer, Muhsine Bilge
DenBaars, S. P.
Speck, J. S.
The fabrication and characterization of metal-semiconductor-metal polarization-sensitive photodetectors based on A-plane GaN grown on R-plane sapphire substrates is reported. These photodetectors take advantage of the in-plane crystal anisotropy, which results in linear dichroism near the band gap energy. The high resistivity of the A-plane GaN material leads to extremely low dark currents. For an optimized finger spacing of 1 mu m, dark current density and responsivity at 30 V are 0.3 nA/mm(2) and 2 A/W, respectively. A maximum polarization sensitivity ratio of 1.8 was determined. In a differential configuration, the full width at half maximum of the polarization-sensitive region is 8.5 nm.


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Polarization anisotropy in GaN films for different nonpolar orientations studied by polarized photoreflectance spectroscopy
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We use photoreflectance (PR) spectroscopy to study the electronic band structure modification of GaN films grown along different nonpolar orientations due to biaxial, anisotropic in-plane strain. The exciton transition energies of an unstrained, high-quality C-plane GaN film are used to accurately determine the crystal-field and spin-orbit splitting energies. For films with a nonpolar orientation, the resonant features observed in the PR spectra exhibit a strong in-plane polarization anisotropy and differen...
Citation Formats
A. Navarro et al., “High responsivity A-plane GaN-based metal-semiconductor-metal photodetectors for polarization-sensitive applications,” APPLIED PHYSICS LETTERS, pp. 0–0, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46507.