Abstract
We demonstrate a novel doping mechanism of silicon, namely -type transfer doping by adsorbed organic cobaltocene () molecules. The amount of transferred charge as a function of coverage is monitored by following the ensuing band bending via surface sensitive core-level photoelectron spectroscopy. The concomitant loss of electrons in the adlayer is quantified by the relative intensities of chemically shifted Co2p components in core-level photoelectron spectroscopy which correspond to charged and neutral molecules. Using a previously developed model for transfer doping, the evolution in relative intensities of the two components as a function of coverage has been reproduced successfully. A single, molecule-specific parameter, the negative donor energy of suffices to describe the self-limiting doping process with a maximum areal density of transferred electrons of in agreement with the measured downward band bending. The advantage of this doping mechanism over conventional doping for nanostructures is addressed.
- Received 4 December 2013
DOI:https://doi.org/10.1103/PhysRevLett.112.155502
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