摘要
Self-trapped excitons(STEs)emission from halide perovskites with strong exciton-phonon coupling has attracted considerable attention due to the widespread application in optoelectronic devices.Nevertheless,the in-depth understanding of the relationship between exciton-phonon coupling and luminescence intensity remains incomplete.Herein,a doping-enhanced exciton-phonon coupling effect is observed in Cs_(3)Cu_(2)I_(5)nanocrystals(NCs),which leads to a remarkable increasement of their STEs emission efficiency.Mechanism study shows that the hetero-valent substitution of Cu+with alkaline-earth metal ions(AE^(2+))causes a greater degree of Jahn-Teller distortion between the ground state and excited state structures of[Cu_(2)I_(5)]_(3)-clusters as evidenced by our spectral analysis and first-principles calculations.As a consequence,an X-ray detector based on these Cs_(3)Cu_(2)I_(5):AE NCs delivers an X-ray imaging resolution of up to 10 lp·mm^(-1) and a low detection limit of 0.37μGyair·s^(-1),disclosing the potential of doping-enhanced exciton-phonon coupling effect in improving STEs-emission and practical application for X-ray imaging.
基金
This work is supported by the Fund of Fujian Science&Technology Innovation Laboratory for Optoelectronic Information(Nos.2020ZZ114 and 2022ZZ204)
the Key Research Program of Frontier Science CAS(No.QYZDY-SSW-SLH025)
the National Natural Science Foundation of China(Nos.21731006 and 21871256)
the Fund of Advanced Energy Science and Technology Guangdong Laboratory(No.DJLTN0200/DJLTN0240).
