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C. P. Sadia, L. P. Lopez, Jr., R. M. delos Santos, J. E. Muldera, A. E. De Los Reyes, M. A. C. Tumanguil, C. T. Que, V. K. Mag-usara, M. Tani, A. S. Somintac, E. S. Estacio, and A. A. Salvador

Thin Solid Films 648, pp. 46 - 49 (2018) [Ref]

We report the molecular beam epitaxy growth of high-quality p-InAs thin films evaluated in the context of 1.55 µm femtosecond laser-excited THz emission efficiency. The presence of p-InAs is confirmed via scanning electron microscopy and x-ray diffraction. Using a GaAs buffer layer, the epitaxial growth of p-InAs layers was successfully achieved. Initiating GaAs deposition by growth interruption, we find that GaAs adheres to the GaSb substrate and provides a quasi-planar surface for the subsequent layers. We also find a significant enhancement in the THz radiation intensity of p-InAs films that is approximately twice compared to that of bulk p-InAs for 1.55 µm wavelength.

Copyright 2018 Elsevier

C. P. Sadia, J. Muldera, E. S. Estacio, A. S. Somintac, A. A. Salvador, C. T. Que, K. Yamamoto, and M. Tani

Applied Physics Express 8, 035501 (2015) [Ref]

We demonstrate molecular beam epitaxy growth of p-InAs layers on GaAs-buffered GaSb that may be suitable for terahertz applications. GaAs buffer deposition is initiated by applying growth interruption. Reflection high-energy electron diffraction shows that GaAs growth proceeds to a quasi-two-dimensional growth mode. The scheme allows growth of a p-InAs layer 600 nm to 1.0 µm thick. Growth performed without GaAs and growth interruption resulted in decomposition of the p-InAs. When the scheme is used, the ensuing p-InAs first follows quasi-two-dimensional growth before favoring faceted islanding. Under 800-nm-wavelength femtosecond laser excitation, the p-InAs layer generates terahertz signals 70% of that of bulk p-InAs. 

Copyright 2015 The Japan Society of Applied Physics