Studies of the electronic transport properties of n-type doped hydrogenated amorphous/nanocrystalline silicon (a/nc-Si:H) films deposited in a dual-plasma co-deposition reactor are described. For these doped a/nc-Si:H, the conductivity increases monotonically for increasing crystal fractions up to 60% and displays marked deviations from a simple thermally activated temperature dependence. Analysis of the temperature dependence of the activation energy for these films finds that the dark conductivity is best described by a power-law temperature dependence, σ= σ o (T/T o) n where n= 1-4, suggesting multiphonon hopping as the main transport mechanism. These results suggest that electronic transport in mixed-phase films occurs through the a-Si:H matrix at lower nanocrystal concentrations and shifts to hopping conduction between clusters of nanocrystals at higher nanocrystal densities.
|Original language||English (US)|
|Title of host publication||Amorphous and Polycrystalline Thin-Film Silicon Science and Technology - 2011|
|Number of pages||6|
|State||Published - 2012|
|Event||2011 MRS Spring Meeting - San Francisco, CA, United States|
Duration: Apr 25 2011 → Apr 29 2011
|Name||Materials Research Society Symposium Proceedings|
|Other||2011 MRS Spring Meeting|
|City||San Francisco, CA|
|Period||4/25/11 → 4/29/11|
Bibliographical noteFunding Information:
This work was partially supported by NSF grant DMR-0705675, the NINN Characterization Facility, the Xcel Energy grant under RDF contract #RD3-25, and the University of Minnesota.