Semimetal hR6-CaSi2 thin film: A transparent contact for Si optoelectronics


Journal of Alloys and Compounds, Q1

Статьи в журналах

A.V. Shevlyagin et al. Semimetal hR6-CaSi2 thin film: a transparent contact for Si optoelectronics // Journal of Alloys and Compounds. - 2022. - T.910. - P. 164893.

Transparent conducting materials (TCMs) provide low cost and effective solution for the modern optoelectronics. However, simultaneous high electrical conductivity and optical transparency in the near-infrared (NIR) and middle-infrared (MIR) spectral ranges remain challenging. This study proposes thin film of the semimetal calcium disilicide (CaSi2) with hR6 polymorph modification to fill this niche. Investigation of the electrical, magnetoresistance and magnetic properties shed light on its semimetal behavior. CaSi2 film grown on Si substrate demonstrates competitive electrical and optical properties from the NIR to MIR ranges compared to commonly used TCMs reaching maximum transmittance of 47% at an important telecommunication wavelength of 1550 nm in addition to the low sheet resistance of 6.6 Ω/sq, which results in high TCM figure of merit of 0.2 Ω−1. Moreover, demonstrated for the first time partial optical transparency of the CaSi2 in the visible range could significantly heighten its applicability for Si-based optoelectronics.