Visualization of GaN surface potential using terahertz emission enhanced by local defects

نویسندگان

  • Yuji Sakai
  • Iwao Kawayama
  • Hidetoshi Nakanishi
  • Masayoshi Tonouchi
چکیده

Wide-gap semiconductors have received significant attention for their advantages over existing semiconductors in energy-efficient power devices. To realize stable and reliable wide-gap semiconductor devices, the basic physical properties, such as the electric properties on the surface and at the interface, should be revealed. Here, we report visualization of terahertz (THz) emission from the surface of GaN, which is excited by ultraviolet femtosecond laser pulses. We found that the THz emission is enhanced by defects related to yellow luminescence, and this phenomenon is explained through the modification of band structures in the surface depletion layer owing to trapped electrons at defect sites. Our results demonstrate that the surface potential in a GaN surface could be detected by laser-induced THz emission. Moreover, this method enables feasible evaluation of the distribution of non-radiative defects, which are undetectable with photoluminescence, and it contributes to the realization normally-off GaN devices.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Synthesis of Serrated GaN Nanowires for Hydrogen Gas Sensors Applications by Plasma-Assisted Vapor Phase Deposition Method

Nowadays, the semiconductor nanowires (NWs) typically used in hydrogen gas sensors. Gallium nitride (GaN) with a wide band gap of 3.4 eV, is one of the best semiconductors for this function. NWs surface roughness have important role in gas sensors performance. In this research, GaN NWs have been synthesized on Si substrate by plasma-assisted vapor phase deposition at different deposition time, ...

متن کامل

The Interaction of HCN Gas on the Surface of Pristine, Ga, N and GaN-Doped (4,4) Armchair Models of BPNTs: A Computational Approach

In this research, the interactions of HCN gas with pristine, Ga-, N- and GaN-doped of boron phosphide nanotube (BPNTs) were investigated by using density function theory (DFT). The structure, electrical and NQR parameters, quantum descriptors involving energy gap, global hardness, global softness, electrophilicity, electronic chemical potential and electronegativity were calculated. The adsorpt...

متن کامل

Surface plasmon-enhanced terahertz emission from a hemicyanine self-assembled monolayer.

Emission of terahertz radiation is observed when surface plasmons are excited on a thin film of gold, in the Kretschmann geometry. When a hemicyanine-terminated alkanethiol self-assembled monolayer of thickness 1.2 nm is deposited on the gold film, stronger terahertz emission is observed. Our experimental results confirm that enhanced terahertz emission is possible from planar gold surfaces whe...

متن کامل

Imaging molecular adsorption and desorption dynamics on graphene using terahertz emission spectroscopy

Being an atomically thin material, graphene is known to be extremely susceptible to its environment, including defects and phonons in the substrate on which it is placed as well as gas molecules that surround it. Thus, any device design using graphene has to take into consideration all surrounding components, and device performance needs to be evaluated in terms of environmental influence. Howe...

متن کامل

Nonpolar Nitride Semiconductor Optoelectronic Devices: a Disruptive Technology for next Generation Army Applications

Nonpolar nitride semiconductor materials containing a wide range of structural defects are studied. High quality InGaN quantum wells grown on bulk stacking fault (SF) -free GaN substrates show larger PL intensity and shorter PL lifetime with decreasing well width, indicating that the radiative lifetime is becoming smaller as the well narrows, consistent with the theoretically predicted increase...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 5  شماره 

صفحات  -

تاریخ انتشار 2015