Superconductivity in CVD Diamond Thin Film Well-Above Liquid Helium Temperature

TL;DR

This paper reports the discovery of superconductivity in boron-doped diamond thin films deposited via CVD, with a transition temperature of 7.4K, significantly above liquid helium temperature, indicating potential for diamond-based electronic devices.

Contribution

It provides the first unambiguous evidence of superconductivity in CVD-grown boron-doped diamond thin films with a higher transition temperature than previously reported.

Findings

Superconductivity observed at 7.4K in CVD diamond films.

Superconductivity is a universal property of boron-doped diamond.

Potential for diamond-based superconducting electronic devices.

Abstract

Diamond has always been adored as a jewel. Even more fascinating is its outstanding physical properties; it is the hardest material known in the world with the highest thermal conductivity. Meanwhile, when we turn to its electrical properties, diamond is a rather featureless electrical insulator. However, with boron doping, it becomes a p-type semiconductor, with boron acting as a charge acceptor. Therefore the recent news of superconductivity in heavily boron-doped diamond synthesized by high pressure sintering was received with considerable surprise. Opening up new possibilities for diamond-based electrical devices, a systematic investigation of these phenomena clearly needs to be achieved. Here we show unambiguous evidence of superconductivity in a diamond thin film deposited by a chemical vapor deposition (CVD) method. Furthermore the onset of the superconducting transition is found to be 7.4K, which is higher than the reported value in ref(7) and well above helium liquid temperature. This finding establishes the superconductivity to be a universal property of boron-doped diamond, demonstrating that device application is indeed a feasible challenge.