Title :
Ultrafast scanning tunneling microscopy using a photoexcited low-temperature-grown GaAs tip
Author :
Donati, G.P. ; Some, D. ; Rodriguez, G. ; Taylor, A.J.
Author_Institution :
Div. of Mater. Sci. & Technol., Los Alamos Nat. Lab., NM, USA
Abstract :
Summary form only given. We describe a novel STM tip consisting of a cleaved GaAs substrate with a 1 /spl mu/m-thick epilayer of low temperature-grown GaAs (LT-GaAs) deposited on the face. Because the LT-GaAs has a carrier lifetime of 1 ps, photoexcitation of the tip with an ultrafast, above bandgap pulse both provides carriers for the tunneling current and photoconductively gates (with ps resolution) the current from the tip. We use this tip to detect picosecond transients on a coplanar stripline and demonstrate a temporal resolution of 1.2 ps in tunneling mode.
Keywords :
III-V semiconductors; epitaxial growth; gallium arsenide; high-speed optical techniques; scanning tunnelling microscopy; semiconductor growth; strip lines; 1 ps; 1.2 ps; GaAs; STM tip; carrier lifetime; cleaved GaAs substrate; coplanar stripline; epilayer; low temperature-grown GaAs; photoconductively gates; photoexcitation; photoexcited low-temperature-grown GaAs tip; picosecond transients; ps resolution; temporal resolution; tunneling current; tunneling mode; ultrafast above bandgap pulse; ultrafast scanning tunneling microscopy; Annealing; Gallium arsenide; Microscopy; Optical devices; Optical materials; Optical refraction; Pulse measurements; Temperature; Tunneling; Ultrafast optics;
Conference_Titel :
Lasers and Electro-Optics, 1998. CLEO 98. Technical Digest. Summaries of papers presented at the Conference on
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
1-55752-339-0
DOI :
10.1109/CLEO.1998.676600
