Conductivity and structure of ErAs nanoparticles embedded in GaAs pn junctions analyzed via conductive atomic force microscopy

We have used conductive atomic force microscopy to investigate the influence of growth temperature on local current flow in GaAs pn junctions with embedded ErAs nanoparticles grown by molecular beam epitaxy. Three sets of samples, one with 1 ML ErAs deposited at different growth temperatures and two grown at 530 °C and 575 °C with varying ErAs depositions, were characterized. Statistical analysis of local current images suggests that the structures grown at 575 °C have about 3 times thicker ErAs nanoparticles than structures grown at 530 °C, resulting in degradation of conductivity due to reduced ErAs coverage. These findings explain previous studies of macroscopic tunnel junctions.

[1]  Y. Silberberg,et al.  Stable and epitaxial metal/III-V semiconductor heterostructures , 1990 .

[2]  N. Jourdan,et al.  Dependence of ErAs Clustering and Er Segregation in ErAs/GaAs Heterostructures on Growth Temperature , 1993 .

[3]  John E. Bowers,et al.  Self-assembled ErAs islands in GaAs: Growth and subpicosecond carrier dynamics , 1999 .

[4]  Arthur C. Gossard,et al.  Growth and microstructure of self-assembled ErAs islands in GaAs , 2000 .

[5]  A. Gossard,et al.  Growth-temperature dependence of the microstructure of ErAs islands in GaAs , 2003 .

[6]  C. Palmstrøm,et al.  Embedded assembly mechanism of stable metal nanocrystals on semiconductor surfaces , 2006 .

[7]  Ali Shakouri,et al.  Demonstration of electron filtering to increase the Seebeck coefficient in In0.53Ga0.47As/In0.53Ga0.28Al0.19As superlattices , 2006 .

[8]  Arnold J. Forman,et al.  Increased efficiency in multijunction solar cells through the incorporation of semimetallic ErAs nanoparticles into the tunnel junction , 2006 .

[9]  Willie J Padilla,et al.  Ultrafast optical switching of terahertz metamaterials fabricated on ErAs/GaAs nanoisland superlattices. , 2007, Optics letters.

[10]  P. Tejedor,et al.  Conductive atomic force microscopy study of InAs growth kinetics on vicinal GaAs (110) , 2009 .

[11]  S. Bank,et al.  Enhanced conductivity of tunnel junctions employing semimetallic nanoparticles through variation in growth temperature and deposition , 2010 .

[12]  E. Yu,et al.  Low defect-mediated reverse-bias leakage in (0001) GaN via high-temperature molecular beam epitaxy , 2010 .

[13]  S. Bank,et al.  Surface segregation effects of erbium in GaAs growth and their implications for optical devices containing ErAs nanostructures , 2011 .

[14]  Scanning capacitance microscopy of ErAs nanoparticles embedded in GaAs pn junctions , 2011 .