Boosting internal quantum efficiency via ultrafast triplet transfer to 2H-MoTe<sub>2</sub> film.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37343104.
- Also identified by DOI 10.1126/sciadv.adg2324 and PMC identifier 10284539.
- Licence recorded as CC BY-NC.
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Abstract
Organic systems often allow to create two triplet spin states (triplet excitons) by converting an initially excited singlet spin state (a singlet exciton). An ideally designed organic/inorganic heterostructure could reach the photovoltaic energy harvest over the Shockley-Queisser (S-Q) limit because of the efficient conversion of triplet excitons into charge carriers. Here, we demonstrate the molybdenum ditelluride (MoTe<sub>2</sub>)/pentacene heterostructure to boost the carrier density via efficient triplet transfer from pentacene to MoTe<sub>2</sub> using ultrafast transient absorption spectroscopy. We observe carrier multiplication by nearly four times by doubling carriers in MoTe<sub>2</sub> via the inverse Auger process and subsequently doubling carriers via triplet extraction from pentacene. We also verify efficient energy conversion by doubling the photocurrent in the MoTe<sub>2</sub>/pentacene film. This puts a step forward to enhancing photovoltaic conversion efficiency beyond the S-Q limit in the organic/inorganic heterostructures.