Controlling optical properties and electronic energy structure of I-III-VI semiconductor quantum dots for improving their photofunctions

I-III-VI multinary semiconductors, which have low toxicity, are attracting much attention as quantum dot (QD) materials for replacing conventional binary semiconductors that contain highly toxic heavy metals, Cd and Pb. Recently, the inherent design flexibility of multinary QDs has also been attracting attention, and optoelectronic property control has been demonstrated in many ways. Besides size control, the electronic and optical properties of multinary QDs can be changed by tuning the chemical composition with various methods including alloying with other semiconductors and deviation from stoichiometry. Due to significant progress in synthetic methods, the quality of such multinary QDs has been improved to a level similar to that of Cd-based binary QDs. Spe-cifically, increased photoluminescence quantum yield and recently narrowed linewidth have led to new appli-cation fields for multinary QDs. In this review, a historical overview of the solution-phase synthesis of I-III-VI QDs is provided and the development of strategies for better control of optoelectronic properties, i.e., electronic structures, energy gap, optical absorption profiles, and photoluminescence feature, is discussed. In addition, applications of these QDs to luminescent devices and light energy conversion systems are described. The per-formance of prepared devices can be improved by controlling the optical properties and electronic structures of QDs by changing their size and composition. Clarification of the unique features of I-III-VI QDs in detail will be the base for further development of novel applications by utilizing the complexity of multinary QDs.

Automated summary

I-III-VI multinary semiconductors, with low toxicity, are being studied as potential quantum dot materials to replace toxic Cd and Pb-based binary semiconductors. The flexibility in design and control of electronic and optical properties of multinary quantum dots has attracted significant attention. This review provides a historical overview of the synthesis of I-III-VI quantum dots and discusses strategies for better control of their optoelectronic properties. Applications in luminescent devices and light energy conversion systems are also discussed, highlighting the potential for improved performance by controlling the size and composition of the quantum dots. Understanding the unique features of I-III-VI quantum dots will enable the development of novel applications utilizing their complexity.