Highly efficient carrier multiplication in PbS nanosheets

Highly efficient carrier multiplication in PbS nanosheets

Aerts, M.
Bielewicz, T.
Klinke, C.
Grozema, F.C.
Houtepen, A.J.
Schins, J.M.
Siebbeles, L.D.A.

Applied Sciences

ChemE/Chemical Engineering

2014-04-30

Semiconductor nanocrystals are promising for use in cheap and highly efficient solar cells. A high efficiency can be achieved by carrier multiplication (CM), which yields multiple electron-hole pairs for a single absorbed photon. Lead chalcogenide nanocrystals are of specific interest, since their band gap can be tuned to be optimal to exploit CM in solar cells. Interestingly, for a given photon energy CM is more efficient in bulk PbS and PbSe, which has been attributed to the higher density of states. Unfortunately, these bulk materials are not useful for solar cells due to their low band gap. Here we demonstrate that two-dimensional PbS nanosheets combine the band gap of a confined system with the high CM efficiency of bulk. Interestingly, in thin PbS nanosheets virtually the entire excess photon energy above the CM threshold is used for CM, in contrast to quantum dots, nanorods and bulk lead chalcogenide materials.

physical sciences
nanotechnology
optical physics

http://resolver.tudelft.nl/uuid:2f646b76-f0b5-4d28-a25b-56222edbcb5d

https://doi.org/10.1038/ncomms4789

Nature Publishing Group

2041-1723

Nature Communications, 5, 2014

Institutional Repository

journal article

(c) 2013 Macmillan Publishers Limited
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