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 (G(D)) characteristics of Ge-QD single-hole transistors (SHTs) in the few-hole regime. Full-voltage width-at-half-minimum, V-1/2, of G(D) valleys appears to be fairly linear in the charge number (n) and temperature within the QD in a relationship of eV(1/2)congruent to(1 - 0.11n) x 5.15k(B)T, providing the primary thermometric quantity. The depth of G(D) valley is also proportional to charging energy (E-C) and 1/T via Delta G(D)congruent to E-C/9.18k(B)T, 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 10 nm and temperature accuracy of sub-kelvin. (C) 2014 AIP Publishing LLC.