Activating Carrier Multiplication in PbSe Quantum Dot Solids by Infilling with Atomic Layer Deposition.
Carrier multiplication-the generation of multiple electron-hole pairs by a single photon-is currently of great interest for the development of highly efficient photovoltaics. We study the effects of infilling PbSe quantum-dot solids with metal oxides by atomic layer deposition on carrier multiplication. Using time-resolved microwave conductivity measurements, we find, for the first time, that carrier multiplication occurs in 1,2-ethanedithiol-linked PbSe quantum-dot solids infilled with Al2O3 or Al2O3/ZnO, while it is negligible or absent in noninfilled films. The carrier-multiplication efficiency of the infilled quantum-dot solids is close to that of solution-dispersed PbSe quantum dots, and not significantly limited by Auger recombination.
†Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
Sybren
S
Ten Cate
‡Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States.
Yao
Y
Liu
†Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
C S
CS
Suchand Sandeep
Sachin
S
Kinge
†Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
Arjan J
AJ
Houtepen
†Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
Tom J
TJ
Savenije
†Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
Juleon M
JM
Schins
‡Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States.
Matt
M
Law
†Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
Laurens D A
LD
Siebbeles
atomic layer deposition; carrier multiplication; multiple exciton generation; quantum dot solid; third-generation solar cell; time-resolved microwave conductivity