Precise Hue Control in a Single‐Component White‐Light Emitting Perovskite Cs₂SnCl₆ through Defect Engineering Based on La³⁺ Doping

Abstract

of effective energy regulation strategies, which facilitates the progress in the development of white light sources. The present commercial WLEDs with high color rendering index (CRI) and tunable correlate color temperature (CCT) are usually consisting of near-ultraviolet/ blue InGaN/GaN chips combined with multiple luminescent components. [1][2][3][4][5][6] However, the fabricating technology of the WLEDs devices based on coating multiple luminescent materials on semiconductor chips is complicated. The self-absorption effects and the different properties of the multiple components usually cause a decrease in luminous efficacy and a deviation in chromaticity color over a long-working time. Therefore, single-component white light emitters, including multiple luminescence centers, are attractive for high stability in a light color and facile fabrication in large quantities of manufacture. [7][8][9] In recent years, the all-inorganic perovskites have evoked tremendous attention due to their excellent optoelectronic properties originating from the formation of selftrapped excitons (STEs) caused by the localized charge distribution and strong carrier-phonon coupling. [10][11][12] The early studies were mainly focused on the multidimensional halide perovskites with intrinsic STE emissions, including 3D (Cs 2 AgInCl 6 PLQY ≈6.5%, Cs 2 NaInCl 6 PLQY ≈7%), 2D (Cs 3 Bi 2 Br 9 PLQY ≈4.5%, Cs 3 Sb 2 Cl 9 PLQY ≈11%), and 1D (CsCu 2 I 3 PLQY ≈9%) perovskites. [13][14][15][16][17] Although these compounds show broadband emission with large Stokes shift, their low PLQYs (< 15%) seriously limit their applications. 0D metal halides of the vacancy-ordered structure have attracted extensive attention because their isolated polyhedral units promote charge recombination, thus facilitating the formation of broadband STE emissions. [18][19][20][21][22][23][24][25] It was reported that the crystals of Bi 3+ /Sb 3+ co-doped Cs 2 ZrCl 6 (PLQY ≈55%) and Bi 3+ /Te 4+ co-doped Cs 2 HfCl 6 (PLQY ≈66%) show efficient dual broad emissions with a high quantum yield, which is assigned to the good compatibility structures of the hosts as well as the effective tailoring the electronic and optical properties via induction of defects. [18][19][20][21] The perovskite compound Cs 2 SnCl 6 was regarded as an excellent host because of its nontoxicity, low cost, simple structure, good compatibility, and electronically decoupled 0D structure that favors the formation of STEs. [22][23][24][25] A new class of white-light emitters based on Bi 3+ Single-component white light emitters based on the all-inorganic perovskites will act as outstanding candidates for applications in solid-state lighting thanks to their abundant energy states for self-trapped excitons (STE) with ultra-high photoluminescence (PL) efficiency. Here, a complementary white light is realized by dual STEs emissions with blue and yellow colors in a single-component perovskite Cs 2 SnCl 6 :La 3+ microcrystal (MC). The dual emission bands centered at 450 and 560 nm are attributed to the intrinsi...

Cs2SnCl6: To Emit or to Catalyze? Te4+ Ion Calls the Shots

“…High‐resolution XPS spectra depicted in Figure 1e show peaks located at around 737.9, 724.0, 586.76, 576.3, 495.9, 487.5, 200.3, and 198.6 eV, which are assignable to Cs + 3d 3/2 , Cs + 3d 5/2 , Te 4+ 3d 3/2 , Te 4+ 3d 5/2 , Sn 4+ 3d 3/2 , Sn 4+ 3d 5/2 , Cl − 2p 1/2 , and Cl − 2p 3/2 , respectively, evidencing the +1 state for Cs, +4 states for both Te and Sn, and −1 state for Cl in the crystal. [ 13 ] A closer look at the XPS spectra shows that the binding energy of Cs 3d remains unchanged with increasing Te content (Figure S2 , Supporting Information), whereas that of Cl 2p and Sn 3d shifts to higher binding energy and that of Te 3d shifts to lower binding energy. These results suggest a possible charge transfer from Cl/Sn to Te.…”

Bandgap Engineering through Fe Doping in Cs2SnCl6 Perovskite: Photoluminescence Characteristics and Electronic Structure Insights

“…One possibility for a single-phase white light emitter is the blending of several dopant ions. 28,29 Various methods have been utilized for the synthesis of perovskite nanomaterials, including sol−gel, chemical, coprecipitation, solid-state, and solvothermal methods. Among these approaches, solvothermal synthesis is often considered a favorable choice due to its advantages, such as controlled size and morphology, low-temperature processing, and the ability to facilitate homogeneous nucleation and growth of perovskite materials.…”

“…Cs 2 SnCl 6 is considered as a prominent host with excellent compatibility for different dopant ions, which includes Bi 3+ , Te 4+ , Sb 3+ , Ce 3+ , Eu 3+ , and Tb 3+ . , In Cs 2 SnCl 6 , the dopant ions can cause the emission of yellow, blue, and red shades. One possibility for a single-phase white light emitter is the blending of several dopant ions. , …”

White light emission in 0D halide perovskite [(CH3)3S]2SnCl6·H2O crystals through variation of doping ns2 ions

“…Through color addition, white light emission can be obtained by co-doping of Bi 3+ and Te 4+ ions [ 28 , 29 ]. Based on the blue emission from the defect of Cs 2 SnCl 6 structure, Ce 3+ doped into Cs 2 SnCl 6 induces an enhanced blue emission [ 30 ], while La 3+ doped into Cs 2 SnCl 6 achieves complementary white light [ 31 ]. Similar luminescence tuning by guest ions has also been reported in (NH 4 ) 2 SnCl 6 [ 32 , 33 ].…”