Abstract
In this review, we discuss several fundamental processes taking place in semiconductor nanocrystals (quantum dots (QDs)) when their electron subsystem interacts with electromagnetic (EM) radiation. The physical phenomena of light emission and EM energy transfer from a QD exciton to other electronic systems such as neighbouring nanocrystals and polarisable 3D (semi-infinite dielectric or metal) and 2D (graphene) materials are considered. In particular, emission decay and FRET rates near a plane interface between two dielectrics or a dielectric and a metal are discussed and their dependence upon relevant parameters is demonstrated. The cases of direct (II–VI) and indirect (silicon) band gap semiconductors are compared. We cover the relevant non-radiative mechanisms such as the Auger process, electron capture on dangling bonds and interaction with phonons. Some further effects, such as multiple exciton generation, are also discussed. The emphasis is on explaining the underlying physics and illustrating it with calculated and experimental results in a comprehensive, tutorial manner.
Highlights
Semiconductor nanostructures form a basis for modern electronic technologies
A more scientific term to distinguish semiconductor NCs with strongly size-dependent electronic and optical properties is Quantum Dot (QD), which will be used in this article
More on the scientific research side, a broad variety of nanostructures can be prepared using colloidal NCs as building blocks, in particular, multilayer structures of QDs of different average size, deposited on different substrates [12]. Combining these structures with other materials, such as organic dielectrics [34], epitaxial quantum well (QW) heterostructures [35], metallic nanoparticles [36,37], patterned metallic surface [38] or graphene [39,40] can result in new interesting effects and applications, which physics is related to the coupling of QD excitons with elementary excitations in the surrounding materials
Summary
Semiconductor nanostructures form a basis for modern electronic technologies. Nowadays, they are employed in a wide range of applications in the fields of optoelectronics, photonics, photovoltaics, biosensing, photocatalysis, etc. More on the scientific research side, a broad variety of nanostructures can be prepared using colloidal NCs as building blocks, in particular, multilayer structures of QDs of different average size, deposited on different substrates [12] Combining these structures with other materials, such as organic dielectrics [34], epitaxial quantum well (QW) heterostructures [35], metallic nanoparticles [36,37], patterned metallic surface [38] or graphene [39,40] can result in new interesting effects and applications, which physics is related to the coupling of QD excitons with elementary excitations (such as surface plasmons or QW excitons) in the surrounding materials.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have