Emission Enhancement of Cu-Doped InP Quantum Dots through Double Shelling Scheme

Abstract

The doping of transition metal ions, such as Cu+ and Mn2+ into a quantum dot (QD) host is one of the useful strategies in tuning its photoluminescence (PL). This study reports on a two-step synthesis of Cu-doped InP QDs double-shelled with ZnSe inner shell/ZnS outer shell. As a consequence of the double shelling-associated effective surface passivation along with optimal doping concentrations, Cu-doped InP/ZnSe/ZnS (InP:Cu/ZnSe/ZnS) QDs yield single Cu dopant-related emissions with high PL quantum yields of 57–58%. This study further attempted to tune PL of Cu-doped QDs through the variation of InP core size, which was implemented by adopting different types of Zn halide used in core synthesis. As the first application of doped InP QDs as electroluminescent (EL) emitters, two representative InP:Cu/ZnSe/ZnS QDs with different Cu concentrations were then employed as active emitting layers of all-solution-processed, multilayered QD-light-emitting diodes (QLEDs) with the state-of-the-art hybrid combination of organic hole transport layer plus inorganic electron transport layers. The EL performances, such as luminance and efficiencies of the resulting QLEDs with different Cu doping concentrations, were compared and discussed.

Predicting Indium Phosphide Quantum Dot Properties from Synthetic Procedures Using Machine Learning

“…We conducted 8 new syntheses of InP QDs to test the prediction accuracy of our models. The experiments were designed based on four procedures found in the literature [40][41][42][43] with minor adjustments such that all reaction parameters were not already included as entries in the dataset used to train the machine learning models. The reaction parameters were also selected such that they were not easily extrapolated from the parent procedures.…”

Ag-Doped ZnInS/ZnS Core/Shell Quantum Dots for Display Applications

“…Kim et al reported a maximum Photoluminescence Quantum Yield (PLQY) of 57−58% with optimal Cu doping in InP QDs having double shelling. 46 However, usually the Cu and Mn ions form radiative centers with no optical filtering for monochromaticity of light. However, silver, belonging to Group I of the Periodic Table and having a nonradiative center, can be used as an efficient nontoxic dopant material that can suppress trap emission of the shell layer and show an optical filtering effect, producing monochromatic light emission.…”

“…Metal ions such as Cu + , and Mn 2+ − have been widely explored as suitable dopants in QDs. Kim et al reported a maximum Photoluminescence Quantum Yield (PLQY) of 57–58% with optimal Cu doping in InP QDs having double shelling . However, usually the Cu and Mn ions form radiative centers with no optical filtering for monochromaticity of light.…”

Quantum Dots and Applications

“…This Special Issue consists of four articles, and they cover a broad range of topics from synthesis and characterization of QDs to fabrication and study of operating mechanisms of QD devices. One of the articles is related to QD materials chemistry and QD-based EL devices [7]. Two articles then focus on QD-based photovoltaic devices [8,9], and the last article proposes a new driving mechanism for a QD device [10].…”

“…Moreover, the team fabricated QLEDs where the synthesized Cu-doped InP QDs were incorporated. This article can serve as a good guide on how to improve the efficiency of heavy-metal-free QDs [7]. Moving to the articles concerning QD-based photovoltaics, Zhang et al presented a device architecture-modified phototransistor with improved performance where perovskite CsPbBr 3 QDs-ZnO QD film hybrids were employed.…”