Semi-transparent Cu2ZnSnS4 solar cells by drop-casting of sol-gel ink. (August 2021)

• Record Type: Journal Article
• Authors: Tseberlidis, Giorgio; Hasan Husien, Amin; Riva, Stefania; Frioni, Luigi; Le Donne, Alessia; Acciarri, Maurizio; Binetti, Simona
• Is Part Of: Solar energy. Volume 224(2021)
• Page Start: 134
• Page End: 141
• Publication Date: 2021-08
• Subjects: Cu2ZnSnS4 -- Bifacial solar cells -- Wet deposition -- Thin-film solar cells -- SCAPS simulation; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2021.05.073
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Semi-transparent substrates were used to provide a Cu2 ZnSnS4 bifacial solar cell. Drop-casting of a precursor ink leads to the formation of Cu2 ZnSnS4 thin films. Both CZTS thin films and related solar devices have been deeply characterized. The enhanced performance of the devices in bifacial setup is demonstrated. Device behaviour has been studied by SCAPS simulation and modelling. Abstract: In current days, the research in the photovoltaic field aims to find and investigate cheap thin-film materials based on earth-abundant element suitable for terawatt era. To this purpose Cu2 ZnSnS4 (CZTS) has been widely studied in the last decade, being structurally analogous to the well-documented Cu(In, Ga)Se2 but featuring inexpensive and abundant components. Recently we have reported a simple and straightforward sol-gel process to produce CZTS-based solar cells demonstrating how it is possible to provide a working device with an easily transferable on an industrial scale and low cost process. In this work we report important improvements to the described above methodology by growing CZTS thin films on a transparent substrate aiming to produce bifacial solar cells suitable for an incorporation into a tandem solar cell architecture. The direct droplet deposition of the precursor ink onto the FTO substrate, leads to the kesterite phase. Gelation and annealing steps, without the addition of further sulphur sources make this procedure suitable for industrial scale-up saving a considerable amount of raw materials. UV–Vis absorption, μ-Raman, Photoluminescence, X-ray diffraction and Energy Dispersive Spectroscopy measurements have been performed on the so-produced thin films. The morphology of the samples has been investigated by scanning electron microscopy, proving the extremely good quality of the material. PV devices with a FTO/Mo/CZTS/CdS/ZnO/AZO architecture were obtained showing η = 1.11% in a bifacial set up. A lower η = 0.99% has been measured by illuminating the front side of the cell only, demonstrating that the bifacial setup allows a +11% efficiency enhancement.