Deciphering the roles of ammonium doping for lead-free (NH4)xCs3- xCu2I5 perovskites to regulate the photoelectronic properties

Zeyao Xu; Linqin Jiang; Hao Xiong; Jiansen Wen; Ping Li; Lingyan Lin; Bo Wu; Aijun Yang; Yu Qiu

doi:10.1039/d3cc01148h

Deciphering the roles of ammonium doping for lead-free (NH₄)_xCs_{3- x}Cu₂I₅ perovskites to regulate the photoelectronic properties

Chem Commun (Camb). 2023 May 9;59(38):5677-5680. doi: 10.1039/d3cc01148h.

Authors

Zeyao Xu^{1

2}, Linqin Jiang², Hao Xiong², Jiansen Wen³, Ping Li², Lingyan Lin², Bo Wu³, Aijun Yang⁴, Yu Qiu²

Affiliations

¹ College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China.
² Key Laboratory of Green Perovskites Application of Fujian Provincial Universities, Fujian Jiangxia University, Fuzhou 350108, China. linqinjiang@fjjxu.edu.cn.
³ College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, China.
⁴ PV Metrology Institute, Fujian Metrology Institute, Fuzhou 350003, China.

PMID: 37052193
DOI: 10.1039/d3cc01148h

Abstract

Inorganic ammonium (NH₄⁺) is the simplest amine cation with perfect symmetry, the smallest radius and many H atoms, allowing itself to be used as a potential dopant in achieving high-quality perovskite materials. As a composition-modulation strategy, NH₄⁺-doped (NH₄)_xCs_3-xCu₂I₅ (0 < x < 1.5) lead-free perovskites were successfully synthesized via the eco-friendly ball milling method in this work. As the ammonium content increases, the lattice constants of (NH₄)_xCs_3-xCu₂I₅ shrink and the grain sizes increase. The doping of NH₄⁺ effectively passivates the lattice defects, suppresses the non-radiative recombination and tunes the energy band structure, resulting in better fluorescence properties. UV-pumped deep-blue LEDs based on (NH₄)_xCs_3-xCu₂I₅ phosphors were fabricated, which showed improved performance and tunable emission. These results demonstrate the potential of the NH₄⁺-doping strategy for improving the performance of lead-free perovskite optoelectronics.