Highly‐Sensitive, Stable, and Fast‐Response Lead‐Free Cs₂AgBiBr₆ Double Perovskite Photodetectors Enabled by Synergistic Engineering of Doping Na⁺/Ce³⁺ and Integrating Ag Nanoparticles Film

Abstract

Lead-free double halide perovskites stand out as a promising material for constructing stable and environmental-friendly photodetectors (PDs) because of the excellent stability and nontoxicity. However, the performance (e.g., detectivity and response speed) of lead-free double halide perovskites based PDs is still low. Herein, highly sensitive, stable, and fast-response Cs 2 AgBiBr 6 perovskite PDs are presented by synergistic engineering of doping optimization of Na + /Ce 3+ and integrating with Ag nanoparticles (NPs). Compared to pristine Cs 2 AgBiBr 6 , Cs 2 AgBiBr 6 :Na + ,Ce 3+ film is endowed with higher crystallization quality and better stability after Na + ,Ce 3+ codoping, toward the reduced defect density, the improved charge mobility. Meanwhile, a significantly enhanced charge extraction and transport in Cs 2 AgBiBr 6 :Na + ,Ce 3+ /Ag NPs hybrid film is achieved by further integrating with Ag NPs. Finally, Cs 2 AgBiBr 6 :Na + ,Ce 3+ /Ag NPs hybrid film-based PDs are developed, delivering high detectivity of 1.34 × 10 12 Jones@460 nm and 1.18 × 10 12 Jones@370 nm, which is the relatively high in lead-free double halide perovskites PDs and exceeds the most results of the previous reports in the ultraviolet and visible range. The devices also show outstanding stability and fast-response time (395 ns). This work opens up a novel frontier for developing lead-free perovskite PDs.

Enhancing broadband blue luminescence efficiency and stability in Bi3+-doped Cs2ZnCl4 nanocrystals from STEs and advancing energy applications

“…Since the Bi 3+ radius is larger than the Zn 2+ radius and some of the bismuth ions are doped into the Cs 2 ZnCl 4 NCs lattice to replace the zinc ions, this results in a slight expansion of the lattice, which also indicates the successful doping of Bi 3+ into the nanocrystalline lattice. [30][31][32][33] Additionally, the diffraction peak intensity of the nanocrystals gradually decreases and the peak broadens with further increase in Bi 3+ doping concentration. The diffraction peaks of nanocrystals with 10% and 20% doping concentrations show the most pronounced changes, with a sharp decrease in peak intensity and significant peak broadening.…”

K-Alloyed Lead-free Double-Perovskite Cs2AgBiBr6 Nanocrystals for Use in Light-Emitting Diodes

“…These results suggested the successful alloying or partial replacement of Ag + with K + , indicating that these synthesized NCs were not a ternary compound (Figure ). , To obtain the actual amount of K + alloying, inductively coupled plasma optical emission spectrometry (ICP-OES) elemental analysis was carried out and the corresponding data are summarized in Table S2.…”

Transformation of Polarization Mechanisms by Dimensional Reduction in Lead-Free Silver Bismuth Bromide Double-Perovskite Thin Films

“…In other studies, Cs 2 AgBiBr 6 was investigated for use in Xray 38,39 or photodetectors, 40−42 for which doping with Na + and Ce 3+ as well as the incorporation of Ag nanoparticles was recently shown to improve the stability, sensitivity, and response time. 42 Also, field-effect transistors (FETs) have been realized. 43,44 Cs 2 AgBiBr 6 exhibits intrinsic p-type conductivity, arising from shallow acceptor states caused by Ag vacancies.…”