PbSe-Based Colloidal Core/Shell Heterostructures for Optoelectronic Applications

Abstract

Lead-based (IV–VI) colloidal quantum dots (QDs) are of widespread scientific and technological interest owing to their size-tunable band-gap energy in the near-infrared optical region. This article reviews the synthesis of PbSe-based heterostructures and their structural and optical investigations at various temperatures. The review focuses on the structures consisting of a PbSe core coated with a PbSexS1–x (0 ≤ x ≤ 1) or CdSe shell. The former-type shells were epitaxially grown on the PbSe core, while the latter-type shells were synthesized using partial cation-exchange. The influence of the QD composition and the ambient conditions, i.e., exposure to oxygen, on the QD optical properties, such as radiative lifetime, Stokes shift, and other temperature-dependent characteristics, was investigated. The study revealed unique properties of core/shell heterostructures of various compositions, which offer the opportunity of fine-tuning the QD electronic structure by changing their architecture. A theoretical model of the QD electronic band structure was developed and correlated with the results of the optical studies. The review also outlines the challenges related to potential applications of colloidal PbSe-based heterostructures.

Lead selenide quantum dots and carbon dots amplify solar conversion capability of a TiO2/CdS photoanode

“…15 In the past, for PbSe QDs prepared by a cation exchange method, varying sized PbSe QDs were obtained and for large sized PbSe QDs, band gaps of about 0.8 eV were obtained. 31 Here, the peak in the NIR region could be due to the intra-gap states introduced by the defects in PbSe QDs. PbS/PbSe QDs are known to have shallow and deep trap states which have been in the past shown to be responsible for prohibiting charge transport and in assisting recombination.…”

Bulk- and layer-heterojunction phototransistors based on poly [2-methoxy-5-(2′-ethylhexyloxy-p-phenylenevinylene)] and PbS quantum dot hybrids

“…[26][27][28] However, traditional field effect transistor (FET) theory is always applied to QD FETs. 7 The transfer characteristics of the two types of hybrid FEpT are closer to the representative curves of QD FETs, and thus traditional FET theory applies to the hybrid devices.…”

Optical properties of type-I PbSe/CdSe core/shell quantum dot

“…These core/shell materials show novel optical properties better than the bare quantum dots [13][14][15]. PbSe related colloidal core/shell heterostructures have been investigated for optoelectronic applications [16]. Nonlinear optical properties associated with the intersubband transitions in some core/shell quantum dots have been investigated with the influence of the shell thickness, impurity, and dielectric environment [17,18].…”