Quantum Dots Microstructural Metrology: From Time‐Resolved Spectroscopy to Spatially Resolved Electron Microscopy

Abstract

Quantum dots (QDs) have gained broad acceptance, applicability, and much interest in current semiconductor technology due to their unique optical and electrical properties. [1,2] QDs are semiconductors with size between 3 and 20 nm where electron and hole wave functions are highly confined. [3] The dimension should be comparable to the Bohr exciton radius of the material, and that leads to discrete energy levels in QD. QDs are attracted by their unique atomiclike narrow emission that can be tuned easily by controlling their size, structure, and composition. [4-6] The optical and electrical properties of QDs are better than organic fluorophores. For instance, QD has high quantum efficiency, excellent color gamut, narrow emission bandwidths, broad color tunability, high photostability, and high air stability. [7] These excellent properties make QD a potential candidate for applications in various fields such as optoelectronics, sensing, and imaging. [1,8-10] QDs are typically composed of group II-VI, III-V, and IV-VI compound semiconductors such as CdS, CdSe, PbS, ZnS, InAs, and ZnInS. [11-16] Because of minimal particle diameter, QDs have a high surface-to-volume ratio, and these surface trap states act as centers for nonradiative transitions that diminish the performance of QDs. This can be overcome by the growth of inorganic shells such as ZnS, CdTe, and CdSe. Various core-shell QDs such as CdSe/ZnS,

Optimal Rule-of-Thumb Design of Nickel–Vanadium Oxides as an Electrochromic Electrode with Ultrahigh Capacity and Ultrafast Color Tunability

“…The obtained atomic molar ratios are close to those used in the precursor solution for the Ni 1– x V x O samples with x ≤ 0.25 (Supporting Information Table S2 and Figure S8). The SAED patterns of the Ni 0.75 V 0.25 O (Figure d) exhibit ring patterns that indicate the polycrystalline nature of the electrode film. − Figure e presents the TEM image of the Ni 0.75 V 0.25 O film, showing its thin, silklike morphology. The HRTEM image in Figure f shows clear lattice fringes, with the lattice fringe spacings of 0.21 and 0.24 nm (Figure g,h) corresponding to the (101) and (110) planes of NiO .…”

Solution-processed colloidal quantum dots for light emission

“…This means that particles can be made to emit or absorb specific wavelengths (colour) of light depending on their size. 6…”

“…This means that particles can be made to emit or absorb specific wavelengths (colour) of light depending on their size. (6) QDs have their electrons and holes confined in 3 dimensions (Figure 2c), making QD a zero-dimensional structure, i.e. there are zero dimensions in which electrons are free to move.…”

Многомасштабное структурирование квантовых точек CdSe/CdS/ZnS в центрифугированных и ленгмюровских пленках

“…Идея создания тонких пленок из наноразмерных объектов типа квантовых точек (QDs) реализуется и получает развитие уже свыше двух десятилетий с ярко выраженной тенденцией ко все более широкому расширению сфер практического применения, например, в оптои наноэлектронике, сенсорике [1][2][3][4][5]. В значительной степени это простимулировано проявлением квантоворазмерных эффектов в QDs [6,7], что обусловлено их физической природой.…”