Quantum dots, a composition or composite including the same, and an electronic device including the same

A quantum dot-polymer composite comprising:

• a polymer matrix;
• and
• a plurality of quantum dots dispersed in the polymer matrix;
• wherein the plurality of quantum dots comprises a quantum dot comprising
• a semiconductor nanocrystal particle;
• a first ligand bound to a surface of the semiconductor nanocrystal particle;
• and
• a second ligand bound to the surface of the semiconductor nanocrystal particle,
• wherein the second ligand comprises a compound represented by Chemical Formula 2-1, Chemical Formula 2-2, or Chemical Formula 2-3:
• Ra-L-(CRR)nSM Chemical Formula 2-1
• RRNCSSM Chemical Formula 2-3
• wherein
• Ra includes hydrogen, a substituted or unsubstituted C1 to C40 alkyl group, a substituted or unsubstituted C2 to C40 alkenyl group, a substituted or unsubstituted C6 to C40 aryl group, a C1 to C10 alkoxy group, or —R1OR′, wherein R1 is a substituted or unsubstituted C1 to C20 alkylene group and R′ is hydrogen or a C1 to C20 linear or branched alkyl group,
• R is the same or different, and is each independently hydrogen or a substituted or unsubstituted C1 to C24 alkyl group,
• n is an integer of 0 to 15,
• L is a direct bond, a sulfonyl group, a carbonyl group, an ether group, a sulfide group, a sulfoxide group, an ester group, an amide group, a substituted or a unsubstituted C1 to C10 alkylene, a C2 to C10 alkenylene, or a combination thereof, and
• M is hydrogen, lithium, sodium, potassium, or a combination thereof,
• wherein the first ligand comprises a compound represented by Chemical Formula 1:
• MA2 Chemical Formula 1
• wherein M is Mg, Ca, or Zn, and each A is the same or different, and is independently a C1 to C10 organic group, a halogen, or a combination thereof, and
• wherein the compound represented by Chemical Formula 1 is an organic metal salt, a halogenated metal, a hydrocarbyl metal, a hydrocarbyl metal halide, or a combination thereof.

A display device comprising a plurality of quantum dots, wherein the plurality of quantum dots comprises a quantum dot comprising:

• a semiconductor nanocrystal particle;
• a first ligand bound to a surface of the semiconductor nanocrystal particle;
• and
• a second ligand bound to the surface of the semiconductor nanocrystal particle,
• wherein the second ligand comprises a compound represented by Chemical Formula 2-1, Chemical Formula 2-2, or Chemical Formula 2-3:
• Ra-L-(CRR)nSM Chemical Formula 2-1
• RRNCSSM Chemical Formula 2-3
• wherein
• Ra includes hydrogen, a substituted or unsubstituted C1 to C40 alkyl group, a substituted or unsubstituted C2 to C40 alkenyl group, a substituted or unsubstituted C6 to C40 aryl group, a C1 to C10 alkoxy group, or —R1OR′, wherein R1 is a substituted or unsubstituted C1 to C20 alkylene group and R′ is hydrogen or a C1 to C20 linear or branched alkyl group,
• R is the same or different, and is each independently hydrogen or a substituted or unsubstituted C1 to C24 alkyl group, n is an integer of 0 to 15,
• L is a direct bond, a sulfonyl group, a carbonyl group, an ether group, a sulfide group, a sulfoxide group, an ester group, an amide group, a substituted or a unsubstituted C1 to C10 alkylene, a C2 to C10 alkenylene, or a combination thereof, and
• M is hydrogen, lithium, sodium, potassium, or a combination thereof,
• wherein the first ligand comprises a compound represented by Chemical Formula 1:
• MA2 Chemical Formula 1
• wherein M is Mg, Ca, or Zn, and each A is the same or different, and is independently a C1 to C10 organic group, a halogen, or a combination thereof, and
• wherein the compound represented by Chemical Formula 1 is an organic metal salt, a halogenated metal, a hydrocarbyl metal, a hydrocarbyl metal halide, or a combination thereof.