Transport across meso-junctions of highly doped Si with different superconductors

• Published in: Physics letters. A 2021-03, Vol.391, p.127115, Article 127115
• Main Authors: Parab, Pradnya, Bose, Sangita
• Format: Article
• Language: English
• Subjects: Highly doped Si; Point contact spectroscopy; Proximity effect; Schottkey Barrier
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2020.127115

•Soft point contact spectroscopy used to study transport between semiconductors (Sm) and superconductors (Sc).•Spectra for n++Si–In junctions of low transparency showed large enhancements in the superconducting energy gap of In.•Presence of Schottky Barrier at the Sm–Sc junctions responsible for the enhanced gaps.•In contrast, spectra of high transparency showed mid-gap features consistent with proximity induced superconductivity.•Our work shows that the transparency of the contact is vital in understanding the transport across Sm–Sc interfaces. We studied the transport properties of meso-junctions of semiconducting (Sm) highly doped Si with different superconductors (Sc) through point contact Andreev reflection (PCAR) spectroscopy. Spectra of low transparency point contacts between Si and In showed an enhancement in the superconducting energy gap of In. This was due to the effect of an additional gap arising from the Schottky barrier at the Sm–Sc interface. For higher transparency Si–Nb and Si–Pb point contacts, no gap enhancement was observed though there were weak sub gap features. These were due to proximity induced interface superconductivity known to occur for Sm–Sc junctions of high transparency.