Toward Mass-Production of Transition Metal Dichalcogenide Solar Cells: Scalable Growth of Photovoltaic-Grade Multilayer WSe2 by Tungsten Selenization

Abstract

Semiconducting transition metal dichalcogenides (TMDs) are promising for high-specific-power photovoltaics due to desirable band gaps, high absorption coefficients, and ideally dangling-bond-free surfaces. Despite their potential, the majority of TMD solar cells are fabricated in a non-scalable fashion using exfoliated materials due to the absence of high-quality, large-area, multilayer TMDs. Here, we present the scalable, thickness-tunable synthesis of multilayer tungsten diselenide (WSe${}_2$) films by selenizing pre-patterned tungsten with either solid source selenium or H${}_2$Se precursors, which leads to smooth, wafer-scale WSe${}_2$ films with a layered van der Waals structure. The films have charge carrier lifetimes up to 144 ns, over 14x higher than large-area TMD films previously demonstrated. Such high carrier lifetimes correspond to power conversion efficiency of ~22% and specific power of ~64 W g${}^{-1}$ in a packaged solar cell, or ~3 W g${}^{-1}$ in a fully-packaged solar module. This paves the way for the mass-production of high-efficiency multilayer WSe${}_2$ solar cells at low cost.

References in corpus (5)

• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Van der Waals Materials for Atomically-Thin Photovoltaics: Promise and Outlook
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Cited by in corpus (1)

• Transition Metal Dichalcogenide Solar Cells for Indoor Energy Harvesting