Boosting the electrical properties of nano-structured (Ga10Se90)-MWCNT bilayer thin films

Abstract

Selenium-based chalcogenide semiconductors are of growing interest for optoelectronic applications due to their high DC conductivity, photoconductivity, and carrier mobility. In this work, Ga₁₀Se₉₀-MWCNT nanocomposite thin films were fabricated via thermal evaporation and subsequently modified using swift heavy ion (SHI) irradiation using 70 MeV Ni⁷⁺ ions at fluences of 1 × 10¹² to 1 × 10¹³ ions per cm². SHI irradiation promoted the homogeneous mixing of CNTs within the GaSe matrix, enhancing the electrical properties through defect engineering and interfacial charge transfer. Characterization via FESEM, EDX, and FTIR confirmed uniform nanoparticle dispersion and strong GaSe-CNT interactions. Post-irradiation, DC conductivity increased from 2.11 × 10⁻⁴ to 2.97 × 10⁻³ Ω⁻¹ cm⁻¹, photoconductivity from 5.16 × 10⁻⁵ to 2.90 × 10⁻³ Ω⁻¹ cm⁻¹, and carrier mobility from 50.9 to 475.1 cm² V⁻¹ s⁻¹. These enhancements are attributed to improved charge transport via CNT networks and SHI-induced acceptor states. The results highlight the tunability of GaSe-CNT composites via SHI, supporting their potential use in advanced optoelectronic devices.