Efficient Energy Transfer in Te⁴⁺-Doped Cs₂ZrCl₆ Vacancy-Ordered Perovskites and Ultrahigh Moisture Stability via A-Site Rb-Alloying Strategy

Abstract

As an effective method to improve the optical properties and stability of perovskite matrix, doped halide perovskites have attracted extensive attention in the field of optoelectronic applications. Herein, a series of all inorganic lead-free Te4+-doped Cs2ZrCl6 vacancy-ordered perovskites were successfully synthesized with different Te-doping concentrations by a solvothermal method, and deliberate Te4+-doping results in green-yellow triplet self-trapped exciton (STE) emission with a high photoluminescence quantum yield (PLQY) of 49.0%. The efficient energy transfer was observed from singlet to triplet emission. Further, the effects of A-site Rb alloying on the optical properties and stability were investigated. We found that A-site Rb alloying and C-site cohalogenation did not change the luminescence properties of Te4+, but the addition of a small amount of Rb+ can improve the PL intensity and moisture stability. Our results provide physical insights into the nS2 Te4+-ion-doping-induced emissive mechanism and shed light on improving the environmental stability for further applications.

Efficient, Stable, and Tunable Cold/Warm White Light from Lead‐Free Halide Double Perovskites Cs2Zr1‐xTexCl6

“…The peak at 375 nm is the same as that reported by Chang et al, which can be assigned to the emission of the Te 4+ . [31] Previous studies have shown Te 4+ is similar to Sb 3+ , its energy band is composed of ground state 1 S 0 , singlet excited state 1 P 1 , and triplet excited state 3 P n (n = 0, 1, 2). The transition 1 S 0 → 1 P 1 is allowed, and the transition 1 S 0 → 3 P 1 is partially allowed through the spin− orbit coupling.…”

“…According to previous reports, the short and long lifetime can be inferred to two kinds of recombination pathways, which could be attributed to the 3 P 1 → 1 S 0 and 3 P 0 → 1 S 0 transitions. [31] When x = 0.1048, the short and long lifetime prolong to 10.58 and 22.14 µs, this can be ascribed to the increase of Te 4+ doping. To further investigate the exciton-phonon coupling effect, temperature-dependent PL of Cs 2 Zr 0.9960 Te 0.0040 Cl 6 solid solutions was characterized.…”

Vacancy‐Ordered Double Perovskite Rb2ZrCl6−xBrx: Facile Synthesis and Insight into Efficient Intrinsic Self‐Trapped Emission

“…(The specific details are discussed in the calculation section) Therefore, here we can obtain the highest PLQY equal 90.2%, which act the best value among the vacancy-ordered double perovskites. [31,45,75,76] Atomic substitution is a primary method for semiconductor bandgap engineering, [81] here, we adopt halogen anion substitution to synthesize a series of mixed halide MCs (Rb 2 ZrCl 6−x Br x , x = 0, 0.5, 1, 1.5, 2). (Details in Synthesis section of the Supporting Information) XRD patterns indicate that all the MCs www.advopticalmat.de exhibit a pure cubic phase retaining the original host structure of Rb 2 ZrCl 6 (Figure 3a).…”

“…(The specific details are discussed in the calculation section) Therefore, here we can obtain the highest PLQY equal 90.2%, which act the best value among the vacancy‐ordered double perovskites. [ 31,45,75,76 ]…”

Advances and Challenges in Two-Dimensional Organic–Inorganic Hybrid Perovskites Toward High-Performance Light-Emitting Diodes

“…From the material point of view, the PLQY and photoexcited charge-carrier lifetime of perovskite materials are closely associated with the realization of efficient PeLED [30,66,67]. In Eq.…”