Terahertz emission from Mg-doped a-plane InN

H. Ahn; Y.-J. Yeh; S. Gwo

doi:10.1117/12.874400

24 January 2011 Terahertz emission from Mg-doped a-plane InN

H. Ahn, Y.-J. Yeh, S. Gwo

Proceedings Volume 7945, Quantum Sensing and Nanophotonic Devices VIII; 79450Z (2011) https://doi.org/10.1117/12.874400
Event: SPIE OPTO, 2011, San Francisco, California, United States

Abstract

We report terahertz (THz) emission from magnesium doped a-plane indium nitride (a-InN:Mg) films with different background carrier density, relative to the Mg-doped InN films grown along the c-axis (c-InN:Mg). Due to its high electron affinity, as-grown InN film is typically n-type and it has extremely high background carrier density, which causes much weaker THz emission than that from other semiconductors, such as InAs. The background carrier density of Mg-doped InN can be widely changed by adjusting the Mg doping level. For c-InN:Mg, THz emission is dramatically enhanced (×500 than that of undoped c-InN) as the background carrier density decreases to a critical value of ~1×10¹⁸cm^-3, which is due to the reduced screening of the photo-Dember field at the lower carrier density. For a-InN, however, intense THz emission (×400 than that of undoped c-InN) is observed for both undoped and Mg-doped a-InN and the enhancement is weakly dependent on the background carrier density. The primary THz radiation mechanism of the aplane InN film is found to be due to the acceleration of photoexcited carriers under the polarization-induced in-plane electric field perpendicular to the a-axis, which effectively enhances the geometrical coupling of the radiation out of semiconductor. The weak dependence of THz radiation on the background carrier density for a-InN shows that in-plane surface field induced-terahertz emission is not affected by the background carrier density. Small, but apparent azimuthal angle dependence of terahertz emission is also observed for a-InN, indicating the additional contribution of nonlinear optical processes on terahertz emission.

Citation Download Citation

H. Ahn, Y.-J. Yeh, and S. Gwo "Terahertz emission from Mg-doped a-plane InN", Proc. SPIE 7945, Quantum Sensing and Nanophotonic Devices VIII, 79450Z (24 January 2011); https://doi.org/10.1117/12.874400

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available