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

Abstract

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.