Title :
Electrical Transport in a Semimetal–Semiconductor Nanocomposite
Author :
Brown, Elliot R. ; Williams, Kimani ; Zhang, Weidong ; Suen, Jonathan Y. ; Lu, Hong ; Zide, J. ; Gossard, A.C.
Author_Institution :
Electr. & Comput. Eng. Dept., Univ. of California, Santa Barbara, CA
fDate :
5/1/2009 12:00:00 AM
Abstract :
Measurements are presented on the low-field electrical conductivity and moderate-field current-voltage characteristics in a nanocomposite structure of ErAs particles in an In0.53Ga0.47As host with Be compensation. The electrical conductivity displays strong temperature dependence with two types of transport mechanisms. At ~ 205 K and above, the low-field conductivity appears to be dominated by free electrons in In0.53Ga0.47As. Between 55 and 205 K, the conductivity is well explained by variable-range hopping, sigma = A exp(-B/T1/4), via Mott´s law. The transport displays a soft breakdown effect at moderate bias fields that grows in threshold field with decreasing temperature. This is attributed to impact ionization of the Be dopants.
Keywords :
III-V semiconductors; beryllium; erbium compounds; gallium arsenide; hopping conduction; impact ionisation; indium compounds; nanocomposites; semiconductor doping; semiconductor-insulator boundaries; Be compensation; ErAs-In0.53Ga0.47As:Be; Mott law; beryllium dopants; breakdown effect; electrical transport; free electrons; impact ionization; low-field electrical conductivity; moderate-field current-voltage characteristics; semimetal-semiconductor nanocomposite structure; temperature 55 K to 205 K; threshold field; variable-range hopping; Hopping conductivity; Mott’s law; semimetal nanoparticles; soft impact ionization;
Journal_Title :
Nanotechnology, IEEE Transactions on
DOI :
10.1109/TNANO.2008.2011764
