TY - JOUR
T1 - Effect of electronic structure on carrier multiplication efficiency
T2 - Comparative study of PbSe and CdSe nanocrystals
AU - Schaller, Richard D.
AU - Petruska, Melissa A.
AU - Klimov, Victor I.
N1 - Funding Information:
This work was supported by the Chemical Sciences, Biosciences and Geosciences Division of the Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy and Los Alamos LDRD funds. R.D.S. is supported by a Frederick Reines Fellowship.
PY - 2005
Y1 - 2005
N2 - Recently, we demonstrated that PbSe nanocrystal quantum dots can efficiently produce multiple electron-hole pairs (excitons) in response to a single absorbed photon. To address the generality of this carrier-multiplication phenomenon to other materials, we perform a comparative study of multiexciton generation in PbSe and CdSe nanocrystals that have distinctly different electronic structures. We find that both materials exhibit high-efficiency carrier multiplication and the activation threshold is lower in CdSe nanocrystals than in PbSe nanocrystals (∼2.5 vs ∼2.9 energy gaps). Furthermore, the efficiencies of multiexciton generation are nearly identical for both materials despite a vast difference in both energy structures and carrier relaxation behaviors, strongly suggesting that this phenomenon is general to quantum-confined semiconductor nanocrystals.
AB - Recently, we demonstrated that PbSe nanocrystal quantum dots can efficiently produce multiple electron-hole pairs (excitons) in response to a single absorbed photon. To address the generality of this carrier-multiplication phenomenon to other materials, we perform a comparative study of multiexciton generation in PbSe and CdSe nanocrystals that have distinctly different electronic structures. We find that both materials exhibit high-efficiency carrier multiplication and the activation threshold is lower in CdSe nanocrystals than in PbSe nanocrystals (∼2.5 vs ∼2.9 energy gaps). Furthermore, the efficiencies of multiexciton generation are nearly identical for both materials despite a vast difference in both energy structures and carrier relaxation behaviors, strongly suggesting that this phenomenon is general to quantum-confined semiconductor nanocrystals.
UR - http://www.scopus.com/inward/record.url?scp=29144502386&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=29144502386&partnerID=8YFLogxK
U2 - 10.1063/1.2142092
DO - 10.1063/1.2142092
M3 - Article
AN - SCOPUS:29144502386
VL - 87
SP - 1
EP - 3
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 25
M1 - 253102
ER -