Skip to Main content Skip to Navigation
Journal articles

Time Resolved Photoemission to Unveil Electronic Coupling Between Absorbing and Transport Layers in a Quantum Dot Based Solar Cell

Abstract : Lead sulfide (PbS) colloidal quantum dots-based photodiodes are remarkable structures obtained via colloidal engineering because of their outstanding optoelectronic performances. They combine surface ligand engineering to design a p-n junction with all solution processability. Here we investigate the PbS diode electronic structure combining static and dynamic photoemissions with transport measurements. We show that the n-type nature of the I-capped PbS CQDs shifts the valence band away from the Fermi level compared to the thiol capped nanocrystals. This change in majority carriers can be probed using time resolved X-ray photoemission spectroscopy (TRXPS). We also prove that the photo-induced binding energy shift depends on the nanoparticle surface chemistry. Finally, we demonstrate the ability of TRXPS to selectively probe the electronic structure of each side of an interface. We explore the PbS/MoO3 interface used as hole extractor in the PbS solar cell, using this method. We demonstrate that the PbS layer photosensitizes the MoO3 layer and that the two layers have a quasi-rigid electrostatic coupling. We identify the band bending occurring on the PbS(EDT)/MoO3 to be a limiting factor for the device performance and suggest strategies to overcome this limitation.
Complete list of metadatas

Cited literature [52 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-02947246
Contributor : Emmanuel Lhuillier <>
Submitted on : Wednesday, September 23, 2020 - 6:16:59 PM
Last modification on : Saturday, October 10, 2020 - 3:25:35 AM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : 2021-03-23

Please log in to resquest access to the document

Identifiers

Citation

Charlie Greboval, Prachi Rastogi, Junling Qu, Audrey Chu, Julien Ramade, et al.. Time Resolved Photoemission to Unveil Electronic Coupling Between Absorbing and Transport Layers in a Quantum Dot Based Solar Cell. Journal of Physical Chemistry C, American Chemical Society, 2020, ⟨10.1021/acs.jpcc.0c06751⟩. ⟨hal-02947246⟩

Share

Metrics

Record views

42