Synthesis And Application Of CuInS₂/ZnS Core/shell Quantum Dots And Carbon Dot Solid Phosphors

Semiconductor quantum dots?QDs?,as a new type of nanomaterials,have unique optical properties and wide application prospects in the field of optoelectronics.However,most of the QDs used in white light emitting diodes?LEDs?contain toxic heavy metals such as cadmium?Cd?and lead?Pb?,which will cause serious damage to our health and living environment.For this reason,people gradually focus on the semiconductor QDs without heavy metals.Among the semiconductor nanomaterials,direct bandgap I-III-VI semiconductor QDs have drawn people's attention,especially green and environmentally friendly CuInS₂ QDs.The photoluminescence?PL?wavelength of CuInS₂ QDs can be tuned by size and composition from visible region to near infrared region.While,the PL quantum yield of CuInS₂ QDs is low due to the defects existed in CuInS₂ QDs.Moreover,the PL of CuInS₂ QDs is always concentrated in red light region and lacks green light component,leading to poor color rendering of the LEDs based on CuInS₂ QDs.In addition,carbon dots?CDs?have the advantages of low toxicity,stable chemical properties,wide excitation wavelength range,simple preparation method,good biocompatibility and excellent optical properties,which are suitable for the application in the field of optoelectronic devices.Therefore,the CDs are introduced to supplement the green light component of the CuInS₂-based LEDs.In this paper,the synthesis methods,optical properties and the applications in LEDs of low toxicity CuInS₂ QDs and CDs are studied.