Hole Transfer from Low Band Gap Quantum Dots to Conjugated Polymers in Organic/Inorganic Hybrid Photovoltaics.
We use photoinduced absorption (PIA) spectroscopy to investigate pathways for photocurrent generation in hybrid organic/inorganic quantum dot bulk heterojunction solar cells. We study blends of the conjugated polymer poly(2,3-bis(2-(hexyldecyl)quinoxaline-5,8-diyl-alt-N-(2-hexyldecyl)dithieno[3,2-b:2',3'-d]pyrrole) (PDTPQx-HD) with PbS quantum dots and find that positively charged polarons are formed on the conjugated polymer following selective photoexcitation of the PbS quantum dots. This result provides a direct spectroscopic fingerprint demonstrating that photoinduced hole transfer occurs from the photoexcited quantum dots to the host polymer. We compute the relative yields of long-lived holes following photoexcitation of both the polymer and quantum dot phases and estimate that more long-lived polarons are produced per photon absorbed by the polymer phase than by the quantum dot phase.
†Department of Chemistry and ‡Department of Chemical Engineering, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Adam E
AE
Colbert
†Department of Chemistry and ‡Department of Chemical Engineering, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Eric M
EM
Janke
†Department of Chemistry and ‡Department of Chemical Engineering, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Stephen T
ST
Hsieh
†Department of Chemistry and ‡Department of Chemical Engineering, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Selvam
S
Subramaniyan
†Department of Chemistry and ‡Department of Chemical Engineering, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Cody W
CW
Schlenker
†Department of Chemistry and ‡Department of Chemical Engineering, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Samson A
SA
Jenekhe
†Department of Chemistry and ‡Department of Chemical Engineering, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
David S
DS
Ginger
PIA; PbS nanocrystal; hole transfer; hybrid solar cell; photoinduced absorption