Figure 7.

(a) Schematic energy diagram of LED devices; the values for the energy levels for FAPbI₃ correspond to those reported in the literature for thin films.¹⁶¹ (b) EL spectra for FaPbI₃ NCs and FA_0.1Cs_0.9PbI₃ NCs. Inset: Photograph of LED using FA_0.1Cs_0.9PbI₃ NCs as the active layer. The use of the ETH logo as a pattern in the LED active layer is done with permission from ETH Zürich. (c) Current density versus voltage (J–V) and radiance versus voltage characteristics shown for FAPbI₃ NC-based devices, and the highest external quantum efficiency versus current density characteristics shown for the FAPbI₃ NC-based devices.