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...
