Ultrafast Charge Generation Enhancement in Nanoscale Polymer Solar Cells with DIO Additive.

ABSTRACT: We study the ultrafast photoexcitation dynamics in PBDTTT-C-T (P51, poly(4,8-bis(5-(2-ethylhexyl)-thiophene-2-yl)-benzo[1,2-b:4,5-b']dithiophene-alt-alkylcarbonyl-thieno[3,4-b]thiophene)) film (~100 nm thickness) and PBDTTT-C-T:PC₇₁BM (P51:PC₇₁BM, phenyl-C₇₁-butyric-acid-methyl ester) nanostructured blend (∼100 nm thickness) with/without DIO(1,8-diiodooctane) additives with sub-10 fs transient absorption (TA). It is revealed that hot-exciton dissociation and vibrational relaxation could occur in P51 with a lifetime of ~160 fs and was hardly affected by DIO. However, the introduction of DIO in P51 brings a longer lifetime of polaron pairs, which could make a contribution to photocarrier generation. In P51:PC₇₁BM nanostructured blends

SUBMITTER: Shi T 

PROVIDER: S-EPMC7692121 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature