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I-III-VI group “green” quantum dots (QDs) are receiving increasing attention in photoelectronic conversion applications. In this work, a facile one-pot route directly dissolving copper iodide, gallium acetylacetonate and selenium powder as precursors into a mixed solution of dodecanethiol, oleylamine (OLA) and octadecene was developed to synthesize Cu-Ga-Se/ZnSe (CGSe/ZnSe) core/shell QDs. The resulting CGSe/ZnSe QDs with a relatively high photoluminescence quantum yield (PL QY) of 77.73% can be obtained and the particle size control from 4.20 to 5.73 nm can be realized via the variation of OLA dosage. The tunable emission from 485 to 630 nm can be acquired by introducing sulfur ion into CGSe host materials (anionic alloying) and varying the Cu/Ga precursor molar ratio. Furthermore, the PL recombination process in CGSe/ZnSe QDs is discussed using the PL decay curve. The proposed one-pot synthesis route for highly efficient color-tunable CGSe/ZnSe QDs is facile, rapid and environmentally-friendly. The as-prepared QDs are promising candidates for the exploration of novel and efficient light-emitting diodes. [ABSTRACT FROM AUTHOR]

All-inorganic CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (QDs), an emerging type of luminescent materials, have drawn extensive attention in recent years. However, the amelioration of their stability is becoming a critical issue. Herein, we present a facile and efficient approach to prepare novel perovskite QDs/metal–organic frameworks (CsPbX3/ZIF-8) composites under ambient-atmospheric conditions. The obtained composites exhibit better properties including high photoluminescence (PL) quantum yields (QYs) (41.2% for green and 34.8% for red), narrow-band emission (20 nm for green and 31 nm for red), and enhanced stability in comparison to bare QDs. Furthermore, their application in a remote-type white-light-emitting device was explored and a wide color gamut (~137% of the National Television System Committee standard) was achieved, verifying that these novel luminescent composites have great prospect in backlight display application. [ABSTRACT FROM AUTHOR]

In this letter, dual-emissive and color-tunable Mn-doped InP/ZnS quantum dots (Mn:InP/ZnS QDs) with the absolute photoluminescence quantum yield (PL QY) up to 78% were successfully synthesized via a growth-doping method. The dual emission of Mn:InP/ZnS QDs is composed of intrinsic emission and Mn-doped emission, which can be tuned by different Mn/In ratios. With the increase of Mn dopant concentration, the intrinsic emission shows a red shift from 485 to 524 nm. The new class of dual-emissive QDs provides potential for future application in white LED. [ABSTRACT FROM AUTHOR]

Transition metal ions doping has been an effective method to optimize the optical properties of quantum dots (QDs) and attracted much interest in recent years. In this work, Cu doped InP/ZnS (Cu:InP/ZnS) QDs have been synthesized via a nucleation-doping method and exhibit dual emission which consists of the intrinsic emission and the dopant emission. With the incremental Cu concentration from 0% to 10%, the dopant emission could be largely tuned from 598 to 707 nm. After introducing Ag ions into Cu:InP/ZnS QDs, the photoluminance (PL) intensity of dual emission gets remarkably enhanced with a PL quantum yield (QY) of 79%, while the emission peak positions change marginally. Through X-ray photoelectron spectroscopy, steady-state and time-resolved PL spectroscopy measurement, it can be concluded that the dopant emission color is mainly dominated by Cu while Ag is conducive to improve the dual emission of Cu and Ag co-doped InP/ZnS QDs. These results would contribute to further understanding dopant-dependent interaction and render this new class of single-phased and dual-emissive QDs a promising future to be applied in white LED. Unlabelled Image • Cu:InP/ZnS quantum dots exhibit intrinsic and dopant emission tuned from 598 to 707 nm varying the ratio of Cu/In. • After introducing Ag into Cu:InP/ZnS QDs, the intensity of dual emission gets remarkablely enhanced with a PL QY of 79%. • This new class of single-phased and dual-emissive QDs exhibit a promising potential to be applied in white LED. [ABSTRACT FROM AUTHOR]

We reported two types of tunable white LEDs (WLEDs) based on high quality the single emissive InP/ZnS quantum dots (QDs) and the dual emissive Ag:InP/ZnS QDs via myristic acid (MA) passivation and Ag doping. The WLEDs with three color InP/ZnS QDs could realize color rendering indices (CRIs) of 97–98, color quality scales (CQSs) of 94–98, and limited luminous efficacies (LLEs) of 238–246 lm/W at correlated color temperatures (CCTs) of 2700 K to 6500 K, and the WLEDs with dual emissive Ag:InP/ZnS and red emissive InP/ZnS QDs could realize CRIs of 90–93, CQSs of 90–93, and LLEs of 223–242 lm/W at CCTs of 2700 K to 4000 K. Finally, their luminous efficacies were estimated. [ABSTRACT FROM AUTHOR]

Cadmium-free InP quantum dots (QDs) exhibit many unique optical properties, and show great promise as light emitting materials. In this work, a series of high-efficient and color-tunable transition metal ions (Cu, Mn) single- and co-doped InP/ZnS QDs with the average size of 3.2–3.7 nm, were firstly prepared via a nucleation-doping method in an organic synthetic route. These three kinds of doped InP/ZnS QDs all exhibit dual emission with one peak position around green region owing to the intrinsic state and the other peak position around orange-red region resulted from dopant emission, the relative intensity of which can be effectively tuned by varying Cu or Mn dopant concentration. The dopant emission of Cu doped InP/ZnS QDs from 572 to 696 nm can be realized via increasing Cu dopant concertration from 0.25% to 10%, while the peak position of dopant emission in Mn doped InP/ZnS QDs system remains unaltered as Mn dopant concentration increasing. Besides, the interaction mechanism of Cu and Mn dopant in co-doped InP/ZnS QDs system was investigated with steady-state and time-resolved PL spectroscopy measurements. The results reveal that the dopant emission is dominated by Cu doping rather than Mn doping. These unique results in doped InP/ZnS QDs would help to understand the fundamental aspects of doping, and the dual-emissive and color-tunable optical properties of single-phase doped InP/ZnS QDs will endow them with great promise as color-converting materials for use in solid-state lighting. [ABSTRACT FROM AUTHOR]

Dual emissive Cd-free quantum dots (QDs) are in great demand for various applications. However, their synthesis has been faced with challenges. Here, we demonstrate the dual emissive Ag:InP/ZnS core/shell QDs with the excellent photoluminescence quantum yield (PL QY) up to 75% and their PL dependence on the reaction temperature, reaction time, the different ZnX 2 (X = I, Cl, and Br) precursors, the ratio of In/Zn and the Ag dopant concentration. The as-prepared Ag:InP/ZnS QDs exhibit dual emission with one peak position of about 492 nm owing to the intrinsic emission, and the other peak position of about 575 nm resulting from Ag-doped emission. These dual emissive QDs are integrated with the commercial GaN-based blue LEDs, and the simulation results show that the Ag:InP/ZnS QDs-based white LEDs could realize bright natural white-lights with the luminous efficacy (LE) of 94.2-98.4 lm/W, the color rendering index (CRI) of 82–83 and the color quality scale (CQS) of 82–83 at different correlated color temperatures (CCT). This unique combination of the above properties makes this new class of dual emissive QDs attractive for white LED applications. [ABSTRACT FROM AUTHOR]

In this work, transition metal ion- doped zinc-based quantum dots (QDs) are synthesized via a greener controllable method to avoid the toxicity of the traditional cadmium-based QDs and broaden the tunable emission. Herein, the tunable emission of Cu-doped ZnInS/ZnS core-shell QDs (Cu:ZnInS/ZnS) can cover from 500 to 620 nm by varying the Cu dopant concentration from 1 to 20% and the maximum quantum yield can reach 49.8%. Based on the single-doped QDs, Cu,Mn co-doped ZnInS/ZnS core-shell QDs (Cu,Mn:ZnInS/ZnS) with a photoluminance (PL) quantum yield of 30.4% are obtained. All the as-synthesized QDs have the zinc blende structure and the average size is about 3.55 nm. Besides, the interaction mechanism between the Cu and Mn dopant luminescence centers is proposed in this work, which is rarely investigated in the previous report. Diffusion priority and energy transfer between these two dopants are supposed to play an important role in the co-doped QDs and Cu ions could affect the splitting of Mn d states. Color coordinates of these doped QDs show the line-tunability from (0.200, 0.397) to (0.408, 0.508) on the Commission Internationale de L'Eclairage (CIE) chromatic diagram, showing a promising potential in high-quality white light output by integration of these QDs with blue chips. [ABSTRACT FROM AUTHOR]