Synthesis, growth and studies of pristine and nickel doped L-valinium picrate crystals for organic light emitting diodes applications

Single crystals of L-Valinium Picrate (LVP), 0.1 mol% Ni²⁺ doped L-Valinium Picrate, and 0.2 mol% Ni ²⁺ doped L-Valinium Picrate were grown by low temperature solution growth method, especially by solvent evaporation technique at ambient temperature. Function groups and modes of vibration were identified by FT-IR studies. The grown crystals belong to monoclinic system which has been revealed by powder XRD. The estimated band gaps were found to be 3.86 eV for LVP, 3.72 eV for 0.1 mol% Ni²⁺ doped LVP, and 3.70 eV for 0.2 mol% Ni²⁺ doped LVP crystals, respectively. The PL excitation wavelength of the grown materials is 370 nm. All the elements (C, N, O, Ni, and Cl) as per molecular formula were present in the EDAX spectrum of the grown materials. The 0.2 mol% Ni²⁺ ion doped LVP materials had higher thermal stability (208 °C) than LVP and 0.1 mol% Ni²⁺ doped LVP.