Realization of solid-state nanothermometer using Ge quantum-dot single-hole transistor in few-hole regime.

Semiconductor Ge quantum-dot (QD) thermometry has been demonstrated based on extraordinary temperature-dependent oscillatory differential conductance (GD) characteristics of Ge-QD single-hole transistors (SHTs) in the few-hole regime. Full-voltage width-at-half-minimum, V1/2, of GD valleys appears to be fairly linear in the charge number (n) and temperature within the QD in a relationship of eV1/2≅(1-0.11n)×5.15kBT, providing the primary thermometric quantity. The depth of GD valley is also proportional to charging energy (EC) and 1/T via δGD EC/9.18kBT, providing another thermometric quantity. This experimental demonstration suggests our Ge-QD SHT offering effective building blocks for nanothermometers over a wide temperature range with a detection temperature as high as 155K in a spatial resolution less than 10nm and temperature accuracy of sub-kelvin. [ABSTRACT FROM AUTHOR]