A penta-silicene nanoribbon-based 3D silicon allotrope with high carrier mobility and thermoelectric performance. Issue 44 (4th November 2022)

• Record Type: Journal Article
• Authors: Shen, Yiheng; Ni, Dongyuan; Chen, Yanyan; Sun, Jie; Wang, Qian
• Is Part Of: Physical chemistry chemical physics. Volume 24:Issue 44(2022)
• Page Start: 27413
• Page End: 27422
• Publication Date: 2022-11-04
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp04042e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : A stable 3D silicon allotrope composed of penta-silicene nanoribbons exhibits high hole mobility, low lattice thermal conductivity and a high ZT value as compared to those of diamond silicon. Abstract : Motivated by the successful synthesis of penta-silicene nanoribbons using various experimental techniques, we design a new 3D silicon allotrope, labeled cco-Si48, by assembling such nanoribbons, confirm its dynamical, thermal and mechanical stabilities, and further study its electron/phonon transport and linear optical properties based on the state-of-the-art theoretical calculations. We find that cco-Si48 is a direct bandgap semiconductor with a gap of 1.46 eV, exhibiting a high hole mobility in the magnitude of 10 3 cm 2 V −1 s −1 and a low lattice thermal conductivity of 6.33 W m −1 K −1 at 300 K. Unlike the commonly reported n-type silicon-based materials with high thermoelectric performance, the p-type cco-Si48 outperforms its n-type counterpart in the thermoelectric figure of merit ( ZT ) value with a considerable value of 0.57 at 800 K. We further demonstrate that the electron–phonon interactions play a critical role in determining the optimal carrier concentrations for the peak ZT values. This work expands penta-silicene nanoribbons to their 3D assembled structure with new features and applications.