DOI: 

Optoelektron. napìvprovìd. teh. 61, 62-86 (2026)


O.G. Kosinov, D.V. Korbutyak, B.N. Kulchytskyi, Yu.P. Kyiak. 


SYNTHESIS METHODS AND OPTICAL PROPERTIES OF CuInS2 TRIPLE SEMICONDUCTOR COMPOUNDS (REVIEW) 


This review is dedicated to the analysis of modern synthesis methods and the investigation of the unique optoelectronic properties of copper indium sulfide CuInS2 (CIS) nanocrystals. CIS compounds belong to the group of I–III–VI ternary semiconductors and are considered an environmentally friendly alternative to traditional cadmium- and lead-based quantum dots (QDs) due to their low toxicity and high biocompatibility.

The paper classifies the main synthesis strategies: organic synthesis (hot-injection, solvothermal, and thermal decomposition methods), which ensures high product crystallinity; aqueous synthesis (hydrothermal, microwave, and biomimetic), distinguished by its eco-friendliness and simplicity; and the rapid solvent-free mechanochemical method.

Special attention is paid to optical characteristics: CIS absorption spectra typically lack clear excitonic peaks and exhibit pronounced Urbach tails caused by lattice defects. CIS photoluminescence (PL) is characterized by a large Stokes shift (200–800 meV) and significant peak widths (FWHM), which are explained by recombination mechanisms through defect states, specifically donor-acceptor pairs (DAP) or confined hole states (CHS).

Methods for increasing the photoluminescence quantum yield (PLQY) are reviewed, including surface passivation with wide-bandgap semiconductor shells (ZnS, CdS) and the implementation of gradient shells (InSx/ZnxGa1-xS), which allow for a record efficiency of up to 89% and a narrowing of the emission spectrum. Finally, the potential applications of CIS in bioimaging, quantum dot-sensitized solar cells (QDSSCs), light-emitting diodes (LEDs), and photocatalysis are summarized.

 

Keywords: ternary quantum dots, CuInS2, synthesis methods, photoluminescence, Stokes shift, surface passivation, bioimaging.