Enhanced Nonlinear Optical Coefficients of MAPbI3 Thin Films by Bismuth Doping

The poor photostability under ambient conditions of hybrid halide perovskites has hindered their recently explored promising nonlinear optical properties. Here, we show how Bi³⁺ can partially substitute Pb²⁺ homogeneously in the commonly studied MAPbI₃, improving both environmental stability and photostability under high laser irradiation. Bi content around 2 atom % produces thin films where the nonlinear refractive (n₂) and absorptive coefficients (β), which modify the refractive index (Δn) of the material with light fluence (I), increase up to factors of 4 and 3.5, respectively, compared to undoped MAPbI₃. Higher doping inhibits the nonlinear parameters; however, the samples show higher fluence damage thresholds. Thus, these results provide a road map on how MAPbI₃ can be engineered for practical cost-effective nonlinear applications by means of Bi doping, including optical limiting devices and multiple-harmonic generation into optoelectronics devices.

Active layer solution-processed NIR-OLEDs based on ternary erbium(iii) complexes with 1,1,1-trifluoro-2,4-pentanedione and different N,N-donors

The impact of the diimide ancillary ligand choice on the EL properties has been assessed for NIR-OLEDs based on three novel Er(iii) fluorinated β-diketonate complexes.