Advancement of transition metal dichalcogenides for solar cells: a perspective

Abstract

During the past decade, transition metal dichalcogenides (TMDs) have demonstrated potential as efficient absorber layers for optical, photovoltaic, and photoelectrochemical applications. This stems from their anisotropic structural and optoelectronic properties. The main indicator of their efficiency is their layered structure, suitable band gap (∼1–2 eV), and high absorption coefficient (∼10⁵ cm⁻¹) for the solar spectrum. However, there are still many challenges that limit material performance for up-scaling and fruitful implementation in industry. Fundamental issues such as passivation layers, back contacts, series resistance, antireflection layers, and defect elimination remain problematic. In this perspective, limiting factors for TMDs in photovoltaics are considered, taking into account past and recent progress, and routes for further improvements are outlined. Currently, the lack of systematic efforts limits significant development and published protocol data on TMDs. Considering expanding interests in the growth of different TMD devices, past and recent progress is analyzed and compared, which is helpful in the search for alternative materials in the future.