Observation of compositional domains within individual copper indium sulfide quantum dots

The origin of photoluminescence in copper indium sulfide (CIS) quantum dots (Qdots) has previously been ascribed to a donor-acceptor pair (DAP) recombination, with a crystal lattice defect implicated as the origin of the donor state. In this study, electron energy-loss spectroscopy (EELS) was used to observe defect-rich compositional domains within individual CIS Qdots, supporting a model of defect-state-mediated photoluminescence for these particles, and identifying them as an ideal model system for future study of lattice defects on Qdot properties

Facile Synthesis of Holothurian-Like γ-MnS/Carbon Nanotube Nanocomposites for Flexible All-Solid-State Supercapacitors

The holothurian-like γ-MnS/carbon nanotube (CNT) nanocomposites are successfully fabricated through a facile two-step hydrothermal method. The γ-MnS@CNT hybrid nanocomposite is an attractive electrode material for supercapacitors as it exhibits excellent electrochemical performance with a high specific capacitance of 641.9 F g−1 and cyclic stability of 94.6 % retention after 3000 cycles at a current density of 0.5 A g−1, which are superior to those of CNTs and pure γ-MnS nanoparticles. Furthermore, the as-fabricated all-solid-state supercapacitor reveals remarkable specific capacitance of 263.5 F g−1, high capacitance retention, and a high energy density of 36.6 Wh kg−1 at a power density of 0.5 kW kg−1. The device maintains its supercapacitor performance well, even under bending or twisting states, indicating the excellent mechanical stability and flexibility of the device. The impressive results demonstrate the great opportunity for practical application of this metal sulfide-based composite in high-performance, flexible energy storage devices and wearable electronics