Yasser Hassan
Oxford University, UK
Title: Facile synthesis of air-stable and highly luminescent red- and blue-emitting perovskite nanocrystals for efficient light emitting devices
Biography
Biography: Yasser Hassan
Abstract
Metal halide perovskites are promising candidates for use in light emitting diodes (LEDs), due to their potential for colour tuneable and high luminescence efficiency. While recent advances in perovskite-based light emitting diodes (PeLEDs) have resulted in external quantum efficiencies (EQEs) exceeding 12.4 % for the green emitters, and infrared emitters based on 3D/2D mixed dimensional perovskites have exceeded 15%, the EQEs of the red and blue emitters still lag behind. A critical issue to date is creating highly emissive and stable perovskite emitter with the desirable emission band gap (especially red and blue region) to achieve full-colour displays and white LEDs. A critical issue to date is creating highly emissive and stable perovskite emitter with the desirable emission band gap (especially red and blue region) to achieve full-colour displays and white LEDs. Herein, we report the preparation and characterization of a highly luminescent air-stable suspension of both red cubic CH3NH3PbI3 perovskite nanocrystals (NCs) and high-quality, stable blue colloidal perovskite CsPbBr3 nanoplatelets. Both the red NCs and the blue nanoplatelets exhibit controlled optoelectronic properties with colour purity in the recommended emitting regions (according to Rec. 2020) of band gaps of 1.96 and 2.65 eV, respectively. Photoluminescence quantum yields (PLQY) exceeding 95% for the red NCs and 92% for the blue was achieved. We demonstrate the utility of these nanocrystals in PeLEDs.