Determination of exciton binding energy using photocurrent spectroscopy of Ge quantum-dot single-hole transistors under CW pumping.

ABSTRACT: We reported exciton binding-energy determination using tunneling-current spectroscopy of Germanium (Ge) quantum dot (QD) single-hole transistors (SHTs) operating in the few-hole regime, under 405-1550 nm wavelength (λ) illumination. When the photon energy is smaller than the bandgap energy (1.46 eV) of a 20 nm Ge QD (for instance, λ = 1310 nm and 1550 nm illuminations), there is no change in the peak voltages of tunneling current spectroscopy even when the irradiation power density reaches as high as 10 µW/µm². In contrast, a considerable shift in the first hole-tunneling current peak towards positive V_G is induced (ΔV_G ≈ 0.08 V at 0.33 nW/µm² and 0.15 V at 1.4 nW/µm²) and even additional photocurrent peaks are created at higher positi

SUBMITTER: Hong PY 

PROVIDER: S-EPMC10471612 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature