Aqueous Based Semiconductor Nanocrystals

Abstract

This review summarizes traditional and recent nonconventional, bioinspired, methods for the aqueous synthesis of colloidal semiconductor quantum dots (QDs). The basic chemistry concepts are critically emphasized at the very beginning as these are strongly correlated with the selection of ligands and the optimal formation of aqueous QDs and their more sophisticated structures. The synergies of biomimetic and biosynthetic methods that can combine biospecific reactivity with the robust and strong optical responses of QDs have also resulted in new approaches to the synthesis of the nanoparticles themselves. A related new avenue is the recent extension of QD synthesis to form nanoparticles endowed with chiral optical properties. The optical characteristics of QD materials and their advanced forms such as core/shell heterostructures, alloys, and doped QDs are discussed: from the design considerations of optical band gap tuning, the control and reduction of the impact of surface traps, the consideration of charge carrier processes that affect emission and energy and charge transfer, to the impact and influence of lattice strain. We also describe the considerable progress in some selected QD applications such as in bioimaging and theranostics. The review concludes with future strategies and identification of key challenges that still need to be resolved in reaching very attractive, scalable, yet versatile aqueous syntheses that may widen the scope of commercial applications for semiconductor nanocrystals.

“Green” Aqueous Synthesis and Advanced Spectral Characterization of Size-Selected Cu2ZnSnS4 Nanocrystal Inks

“…Simultaneously, the trend to utilize concentrated CZTS NC inks for the solution-based production of microcrystalline CZTS/CZTSe solar cell absorbers becomes ever more pronounced in the last years 3–5,10,14 . All these factors stimulated the development of new synthetic approaches allowing CZTS NCs with a defined size, lattice type, shape, and composition to be produced 6,7,10,11,15,16 .…”

Emergence of Nanoplatelet Light-Emitting Diodes

“…Currently, some QD-LED TVs are also available in the display markets. With the studying of CdSe QDs, CdSe based other nanostructures have been achieved [4,5,6,7,8,9]. …”

Light‐Emitting Diodes with Cu‐Doped Colloidal Quantum Wells: From Ultrapure Green, Tunable Dual‐Emission to White Light

“…As a new type of nanocrystal LEDs, CQW‐LEDs have great potential for displays and lighting thanks to their merits such as outstanding color purity, low power consumption, high efficiency, and flexibility . The first CQW‐LED was emerged in 2014, which was two decades later than the first CQD‐LED .…”