Superconductivity in carrier-doped silicon carbide

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid-State Chemistry

Background:

• Silicon carbide (SiC) is a wide-bandgap semiconductor with potential applications in electronics and power devices.
• Superconductivity in semiconductors is a developing field with implications for novel electronic devices.
• Doping semiconductors with elements like Boron (B) and Aluminum (Al) can alter their electronic properties.

Purpose of the Study:

• To investigate the superconducting properties of heavily doped silicon carbide (SiC) with Boron (B) and Aluminum (Al).
• To characterize the type of superconductivity (Type-I or Type-II) and critical temperature (Tc) in doped SiC.
• To understand the relationship between acceptor ionization energies and superconducting behavior in p-type semiconductors.

Main Methods:

• Growth of heavily boron-doped 3C-SiC and 6H-SiC.
• Growth of heavily aluminum-doped 3C-SiC.
• Characterization of superconducting properties, including critical temperature (Tc), zero resistivity, and diamagnetic susceptibility.
• Analysis of effective hole-carrier concentration (n).

Main Results:

• Both boron-doped 3C-SiC (3C-SiC:B) and 6H-SiC (6H-SiC:B) exhibited Type-I superconductivity with a critical temperature (Tc) of 1.5 K.
• Aluminum-doped 3C-SiC (3C-SiC:Al) displayed Type-II superconductivity with a Tc of 1.4 K.
• Both SiC:Al and SiC:B showed zero resistivity and diamagnetic susceptibility below their respective Tc, with hole-carrier concentrations exceeding 10^20 cm^-3.

Conclusions:

• Carrier-doped p-type semiconductors like SiC:Al and SiC:B can exhibit superconductivity.
• The observed differences in superconducting behavior are attributed to the varying ionization energies of the acceptor dopants (Al and B).
• This study contributes to understanding superconductivity mechanisms in doped semiconductors.