Optical Property Regulation through Host–Guest Interaction in a Zero-Dimensional Zr Chloride

Halide perovskites, particularly zero-dimensional (0D) A 2 BX 6 -type structures, have garnered significant attention in diverse fields due to their exceptional photoelectric properties. This study focuses on the optical property regulation of 0D A 2 ZrCl 6 through nonprotonated cation substitution (A = [(CH 3 ) 3 SO] + and [(CH 3 ) 4 N] + ) combined with different guest ions (i.e., Sb 3+, Bi 3+, and Mn 2+ ). The varied host–guest interaction is regarded as the reason for the different luminescent behaviors. The Sb 3+ dopant has a weaker interaction with the host [(CH 3 ) 3 SO] 2 ZrCl 6 than Mn 2+ does. As a result, Sb 3+ @[(CH 3 ) 3 SO] 2 ZrCl 6 shows an excitation-dependent photoluminescence ranging from blue to orange, while Mn 2+ @[(CH 3 ) 3 SO] 2 ZrCl 6 exhibits only Mn 2+ dopant emission under different excitation wavelengths. Besides the dopant effect on the host–guest interaction, the organic cation can impact the host–guest behavior as well. [(CH 3 ) 3 SO] 2 ZrCl 6 and [(CH 3 ) 4 N] 2 ZrCl 6 have different preferences for dopant ions. Sb 3+ and Mn 2+ are favorable in the host [(CH 3 ) 3 SO] 2 ZrCl 6, while Sb 3+ and Bi 3+ are adopted in [(CH 3 ) 4 N] 2 ZrCl 6 . Due to the varied emission colors from Sb 3+ and Bi 3+ dopants, [(CH 3 ) 4 N] 2 ZrCl 6 possesses diverse photoluminescence behaviors through dopant engineering. Inside [(CH 3 ) 4 N] 2 ZrCl 6, Sb 3+ and Bi 3+ have a weak host–guest interaction, showing a varied PL from the host and guest emission centers under different excitations.