Tailoring Electronic Properties of Colloidal Quantum Dots for Efficient Optoelectronics

Colloidal quantum dots (CQDs) are nanocrystals synthesized in solution, boasting remarkable optical properties and notable electronic characteristics, such as size-tunable bandgaps and high photoluminescence quantum yield. These features, coupled with solution processability, position CQDs as potential candidates for cost-effective and high-performance optoelectronic devices. However, several technological challenges hinder the full exploitation of CQDs in optoelectronics. Among these is the need for long insulating organic ligands in liquid-phase synthesis, which restrict efficient charge injection and transport in quantum dot (QD) films. Furthermore, the high surface-to-volume ratios and core-shell structures prompt complexities in terms of doping and modifying electronic properties. The colloidal nature of quantum dots (QDs) also raises challenges regarding controlled deposition and patterning, which are critical for device fabrication. In this review, the imperative is outlined to tailor CQDs for optoelectronic applications, the limitations that obstruct the implementation of desired modifications are elaborated on, and the specific hurdles confronting electronic coupling, targeted doping, and precision patterning of CQDs are focused on. Additionally, herein, a summary of the solutions proposed to date is offered, insights are shared on the discussed topics, and areas warranting future investigation are highlighted. Realization of efficient optoelectronic devices using colloidal quantum dots (CQDs) demands effective control over the electrical transport properties, doping levels, and geometric patterns. In this review, the key challenges associated with achieving robust electronic coupling, controlled doping, and accurate patterning of CQDs are comprehensively outlined, the reported remedies are critically evaluated, and insightful perspectives are provided on these topics.image (c) 2024 WILEY-VCH GmbH