Colloidal CdSe(1-x)S(x) Nanoplatelets with Narrow and Continuously-Tunable Electroluminescence.

Colloidal nanoplatelets, quasi-two-dimensional quantum wells, have recently been introduced as colloidal semiconductor materials with the narrowest known photoluminescence line width (∼10 nm). Unfortunately, these materials have not been shown to have continuously tunable emission but rather emit at discrete wavelengths that depend strictly on atomic-layer thickness. Herein, we report a new synthesis approach that overcomes this issue: by alloying CdSe colloidal nanoplatelets with CdS, we finely tune the emission spectrum while still leveraging atomic-scale thickness control.

Exciton-stimulated molecular transformation in organic light-emitting diodes.

An exciton-stimulated molecular transformation in an organic light-emitting diode (OLED) on a time scale of a few seconds under electrical bias is shown to reach nearly 100% under standard operating conditions, leading to color switching. It is reversible in both a thin film and an OLED when sufficient thermal energy is supplied. Such an exciton-stimulated molecular transformation suggests a new process which may be exploited for applications such as electrochromic and memory devices.