Tin-halide perovskites (THPs, cubic crystal structure with a chemical formula of ASnX3, A=formanidinium (FA+), methylammonium (MA+), and/or Cs+; X = Br– and/or I–) have emerged as one of the most promising candidates for NIR-LED application. They can readily tune the emission from 680 to 950 nm through mixing Br and I anions. Mixing Sn and a little amount of another metal (e.g., Pb) can further extend the emission up to 1000 nm through bandgap bowing effect. On top they present a reduced toxicity, following the requirements of the European Green Deal, which asks for reducing pollution to enhance the protection of human life, animals, and plants.
