Inorganic perovskites improved film and crystal quality of CsPbIBr2 when doped with rubidium

• Published in: Journal of materials science. Materials in electronics 2021-10, Vol.32 (20), p.24825-24833
• Main Authors: Stewart, Alexander W., Bouich, Amal, Marí, Bernabé
• Format: Article
• Language: English
• Subjects: Absorptivity; Cesium; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystallites; Energy gap; Materials Science; Morphology; Optical and Electronic Materials; Optoelectronics; Perovskites; Photoluminescence; Pinholes; Radiation; Relative humidity; Rubidium; Spectrum analysis; Thin films
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-06941-z

In this work CsPbIBr 2 is doped with rubidium, where up to 12% of caesium atoms are replaced with those of rubidium. The obtained Cs 1 − x Rb x PbIBr 2 , x= (0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.12), films were characterized by X-ray diffraction (XRD), the scanning electron microscope (SEM), photoluminescence (PL) and UV–visible spectroscopy. The integration of Rb + ions into the lattice leads to a detectable change in optoelectronic and morphological structure. Substituting 6% of caesium atoms yields the best results, eliminating pinholes and elevating crystallite size and absorption coefficient by 116 and 125%, respectively. Other novel observations, of particular interest, include a slight increase in band-gap energy from 2.1 eV to 2.14 eV and a decrease in stability. Over a period of 15 days, where temperature and relative humidity kept at 23 °C and 20%, respectively, a larger amount of degradation was seen to take place as rubidium content was increased. Therefore, the doping of CsPbIBr 2 with rubidium is most useful in the case where specifically film and crystal quality are desired to be targeted.