Electronic transport in films of colloidal CdSe nanocrystals

Physical Review B - Condensed Matter and Materials Physics

Volumn 66, Issue 7, 2002, Pages 1-9

  Morgan, Nicole Y ^a   Leatherdale, C A ^a   Drndic M ^a   Jarosz, Mirna V ^a   Kastner, Marc A ^a   Bawendi, Moungi ^a  

^a MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 80054982091     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.66.075339     Document Type: Article

References (26)

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13. Other measurements, made on substrates with circular electrodes, are consistent with those shown here; for these devices, the active area of the film lies inside the outer electrode, and so the similarity of the results confirms this picture.
14. A stretched exponential decay will always be concave downward on a log-log plot, although with (formula presented) the form approaches a straight line. Here we choose a characteristic time of (formula presented), an order of magnitude shorter than our earliest measurement time; longer values of (formula presented) would show still more curvature. In the data from the sandwich structures of Ref. 8, typical values of (formula presented) were 10-500 s.
15. Although charge spreads into the film in all directions from the source electrode, the measured current arises only from charge which either passes into, or moves near to (relative to the thickness of the gate oxide), the drain electrode. More distant charge will be screened by the gate electrode, which is grounded for the measurement. Therefore, when estimating the possible contribution of stored charge to the measured current, we consider only the area of the film between the electrodes. Even if the entire surface of the substrate, except for the drain electrode, were charged to (formula presented) this measurement would be sensitive only to charge around the perimeter of the electrode, leading to a correction of less than a factor of 10.
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