Control of the carrier type in InAs nanocrystal films by predeposition incorporation of Cd

Publication Type:

Journal Article


ACS Nano, ACS Publications, Volume 4, Issue 12, p.7373-7378 (2010)




2010, 2013 and earlier


Nanocrystal (NC) films have been proposed as an alternative to bulk semiconductors for electronic applications such as solar cells and
photodetectors. One outstanding challenge in NC electronics is to robustly
control the carrier type to create stable p-n homojunction-based devices.
We demonstrate that the postsynthetic addition of Cd to InAs nanocrystals
switches the resulting InAs:Cd NC films from n-type to p-type when
operating in a field effect transistor. This method presents a stable,
facile way to control the carrier type of InAs nanocrystals prior to
deposition. We present two mechanisms to explain the observed switch in
carrier type. In mechanism 1, Cd atoms are incorporated at In sites in the
lattice and act as acceptor defects, forming a partially compensated
p-type semiconductor. In mechanism 2, Cd atoms passivate donor-type InAs
surface states and create acceptor-type surface states. This work
represents a critical step toward the creation of p-n homojunction-based
NC electronics.


PMID: 21126000