Single-Electron Transport in Colloidal Quantum Dots of Narrow-Gap Semiconductors

2022

According to the current-voltage characteristics (CVC) and absorption spectra of colloidal quantum dots QD-InSb, -PbS, -HgSe on random samples, the manifestations of charge instability appear in the form of single current peaks and quasi-periodic deviations from the monotonic dependence of the CVC, are determined and studied. The results are explained by dimensional electron quantization in the model of a deep extended potential well and depending on the ratios of the quantization size and the de Broglie wavelength for an electron. It is assumed that the manifestation of Bloch oscillations has been experimentally confirmed. The data on the studied processes are determined and summarized in a table. Keywords: Quantum dot, nanocrystal, size quantization, quantum selection, Coulomb constraint, Bloch oscillations.

supporting

confidence: 80%

“…The general nature of CVC is determined by the motion of an electron inside QD and emission therefrom. As demonstrated in our papers [11,19], such phenomena are due to mechanisms of Coulomb limitation in QD and tunneling through its boundary barriers. Fig.…”

mentioning

confidence: 77%

Size quantization and charge instability in colloidal quantum dots of narrow-gap semiconductors

Сергеев

Gavrikov

2022

“…CVCs of nanoparticles without singularities, as shown in a number of our works [10,13], are defined by mechanisms of electron tunneling through potential barrier (the barrier tunneling) (I ∼ exp[αV ]) and Coulomb current limitation by space charge (I ∼ V β ). Fig.…”

mentioning

confidence: 99%

Electron transport in single colloidal quantum dots in an interelectrode nanogap

Gavrikov

2022

Based on the current-voltage characteristics of single colloidal QDs -InSb, -PbS, -HgSe, -CdSe quantum dots, on random samples statistically determined and investigated the mechanisms of barrier and ballistic tunneling, Coulomb confinement, quasi-periodic modulation of electron transport in the model of a deep extended potential well and depending on QDs size and de Broglie wavelength for the electron. The possibility of manifestation of Bloch oscillations has been experimentally confirmed. The parameters of all investigated processes were determined and tabulated. Keywords: Nanoparticle, quantum dot, dimensional quantization, quantum selection, barrier and ballistic tunneling, Coulomb confinement, Coulomb ladder, Bloch oscillations.

“…The aim of the present study is to investigate the specifics of emissive properties of the most thoroughly studied quantum-dimensional particles of narrow-gap semiconductors: QP-PbS and QP-InSb. QPs were produced by colloidal synthesis [7] and examined by photoluminescence spectroscopy [6], transmission electron microscopy (TEM) [8], and CVC (current-voltage curve) analysis [9].…”

mentioning

confidence: 99%

Features of the radiative properties of quantum-size particles of narrow-gap semiconductors

Сергеев

Hazanov

et al. 2022

For colloidal quantum-size particles (QP) of narrow-gap semiconductors, in contrast to quantum dots of wide-gap CdSe, in QP-PbS there take place an anomalous temperature dependence of the photoluminescence intensity. Also, in the planar microstructure containing QP-InSb, long-wavelength radiation (more than 3 μm) and photoconductivity (over 20 μm) was observed. Under certain conditions, the radiation intensity and photoconductivity demonstrate a resonance maximum. The effects were explained in the model of a one-dimensional quantum oscillator, which energy substantially depends on the effective mass of its quasi-free electron. This leads to competition between the manifestations of long-wave radiation and photoluminescence, and hence, to the anomalous temperature dependence of photoluminescence. It is assumed that QP-InSb in a planar microstructure can be sources and receivers of terahertz radiation, which properties depend on the crystal structure of quantum-sized particles determined by the parameters of their synthesis. Keywords: quantum-dimensional particle, quantum dot, narrow-gap semiconductor, effective mass, Brillouin zone, dimensional quantization, quantum oscillator, photoluminescence, long-wavelength radiation.