Properties of Aluminium Thin Films on Polyimide Plastics as Back Contacts in Thin Film Silicon Solar Cells

Abstract:

Aluminium (Al) thin films on polyimide (PI) plastic substrates prepared via thermal evaporation technique and annealed in nitrogen (N₂) ambient at different temperatures (250 - 400°C, for 30 minutes) have been investigated. Structural properties of the as-evaporated film have been studied by high resolution X-ray diffraction (HR-XRD). The result illustrates crystalline nature of the Al thin film with a dominant Al (111) peak at 2θ = 38.4°. Atomic force microscope (AFM) shows increased surface roughness root mean square (RMS) with increased annealing temperature (with roughness of 11.96 nm at 400°C). Sheet resistance drops with increased temperature and records the lowest reading (64 mΩ/) at 400°C. Besides, increased annealing temperature also results in reduced surface reflectance (with minimum reflectance of 73% reflectance in the visible region at 400°C). The effects of the resulting Al back contact properties towards thin film silicon (Si) solar cells on PI substrates were subsequently discussed.

• Periodical: Advanced Materials Research (Volume 620)
• Pages: 474-479
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.620.474
• Online since: December 2012
• Authors: Mohd Zamir Pakhuruddin, Kamarulazizi Ibrahim, Azlan Abdul Aziz
• Keywords: Atomic Force Microscope (AFM), Polyimide, Solar Cell, Surface Reflectance

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