Demonstration of midinfrared type-II InAs/GaSb superlattice photodiodes grown on GaAs substrate

• Published in: Applied physics letters 2009-06, Vol.94 (22), p.223506-223506-3
• Main Authors: Nguyen, Binh-Minh, Hoffman, Darin, Huang, Edward Kwei-wei, Bogdanov, Simeon, Delaunay, Pierre-Yves, Razeghi, Manijeh, Tidrow, Meimei Z.
• Format: Article
• Language: English
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.3148326

We report the growth and characterization of type-II InAs/GaSb superlattice photodiodes grown on a GaAs substrate. Through a low nucleation temperature and a reduced growth rate, a smooth GaSb surface was obtained on the GaAs substrate with clear atomic steps and low roughness morphology. On the top of the GaSb buffer, a p + - i - n + type-II InAs/GaSb superlattice photodiode was grown with a designed cutoff wavelength of 4   μ m . The detector exhibited a differential resistance at zero bias ( R 0 A ) in excess of 1600   Ω cm 2 and a quantum efficiency of 36.4% at 77 K, providing a specific detectivity of 6 × 10 11   cm Hz / W and a background limited operating temperature of 100 K with a 300 K background. Uncooled detectors showed similar performance to those grown on GaSb substrates with a carrier lifetime of 110 ns and a detectivity of 6 × 10 8   cm Hz / W .