Terahertz emission from Mg-doped a-plane InN

Hyeyoung Ahn*, Y. J. Yeh, S. Gwo

*此作品的通信作者

研究成果: Conference contribution同行評審

摘要

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.

原文English
主出版物標題Quantum Sensing and Nanophotonic Devices VIII
DOIs
出版狀態Published - 2011
事件Quantum Sensing and Nanophotonic Devices VIII - San Francisco, CA, United States
持續時間: 23 1月 201127 1月 2011

出版系列

名字Proceedings of SPIE - The International Society for Optical Engineering
7945
ISSN(列印)0277-786X

Conference

ConferenceQuantum Sensing and Nanophotonic Devices VIII
國家/地區United States
城市San Francisco, CA
期間23/01/1127/01/11

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