2D Semiconductors

Solution processed transition metal dichalcogenide nanoflakes

The recently-discovered unique optoelectronic properties and chemical robustness of mono- or few-layer two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) such as MoS2, WS2, MoSe2, and WSe2 have opened new possibilities for solar energy conversion devices. However solar energy conversion on a globally-relevant scale with TMDs requires the ability to fabricate high-performance large-area thin films of these materials using scalable, low-cost techniques, which remains an ongoing challenge. LIMNO is uses solution-based exfoliation and processing techniques to prepare thin films of 2D TMDs for photovoltaic and photoelectrochemical application.  We seek for an increased fundamental understanding of defect states, grain boundaries, interfacial effects, photo-generated charge carrier dynamics, and improved control over thin film morphology/quality. See below for selected publications in this topic.

LIMNO’s liquid-liquid interfacial 2D nanoflake self-assembly thin film deposition technique. a) shows a schematic of the deposition method. b) displays a transmission electron micrograph of a MoS2 flake produced by the liquid assisted exfoliation method.

Representative publications:

Defect Mitigation of Solution-Processed 2D WSe2 Nanoflakes for Solar-to-Hydrogen Conversion

X. Yu; N. Guijarro; M. Johnson; K. Sivula 

Nano Letters. 2018. Vol. 18, num. 1, p. 215-222. DOI : 10.1021/acs.nanolett.7b03948.

Photogenerated Charge Harvesting and Recombination in Photocathodes of Solvent-Exfoliated WSe2

X. Yu; K. Sivula 

Chemistry Of Materials. 2017. Vol. 29, num. 16, p. 6863-6875. DOI : 10.1021/acs.chemmater.7b02018.

Hybrid Heterojunctions of Solution-Processed Semiconducting 2D Transition Metal Dichalcogenides

X. Yu; A. Rahmanudin; X. A. Jeanbourquin; D. Tsokkou; N. Guijarro et al. 

Acs Energy Letters. 2017. Vol. 2, num. 2, p. 524-531. DOI : 10.1021/acsenergylett.6b00707.

Self-assembled 2D WSe2 thin films for photoelectrochemical hydrogen production

X. Yu; M. S. Prévot; N. Guijarro; K. Sivula 

Nature Communications. 2015. Vol. 6, p. 7596. DOI : 10.1038/ncomms8596.