A series of Sm³⁺ activated Ca₉Bi(PO₄)₇ novel tunable orange-red-emitting nanophosphors with an intense emission band at 600 nm were synthesized using the solution combustion method. The crystal structure, phase purity, structural parameters, optical band gap values, photoluminescence (PL) behavior, energy transfer, quantum efficiencies, lifetime values, and CIE chromaticity index of Ca₉Bi_(1-x)Sm_x(PO₄)₇ white powdered samples were consistently analyzed. Rietveld refinement of Ca₉Bi_0.88(PO₄)₇:012Sm³⁺ sample resulted into a trigonal crystal structure of sample having space group R3c(161) with refinement converged to R_p = 7.62%, R_wp = 12.01%, and ꭓ² = 2.08. Meanwhile, the average crystallite size for Ca₉Bi_0.88Sm_0.12(PO₄)₇ system was found out to be nearly 60 nm which was also supported by TEM images. The energy band-gap (E_g) value of Ca₉Bi_0.88Sm_0.12(PO₄)₇ was estimated to be 4.07 eV and the critical distance between Sm³⁺ ions was calculated to be 21.09 Å. The optimum concentration of dopant Sm³⁺ ions in Ca₉Bi(PO₄)₇ sample was ascertained to be 12 mol% and as per Dexter's theory and Huang study, the mechanism behind energy transfer between Sm³⁺ ions was concluded as dipole-dipole interactions. Under excitation at 403 nm, these nanophosphors exhibited three bands in the PL emission spectrum peaking at 562 nm, 600 nm, and 646 nm corresponding to ⁴G_5/2 → ⁶H_J transitions (J = 5/2, 7/2, and 9/2, respectively). A decrease in lifetime values from 1.95 ms to 1.39 ms was observed with increased Sm³⁺ ions concentration. Upon employing Auzel's fitting function, radiative lifetime; non-radiative rates, and quantum efficiencies for as-synthesized nanophosphors were measured. The CIE color coordinate of Ca₉Bi_0.88(PO₄)₇:0.12Sm³⁺ was found to be (0.435, 0.354) and the corresponding quantum efficiency was estimated at 70.6%. The results obtained from our current study indicate that Ca₉Bi(PO₄)₇ doped with Sm³⁺ ions can have applicability as a promising orange-red-emitting nanophosphor for near-UV energized WLEDs.

利用固溶燃烧法合成了一系列具有600nm强发射带的Sm ³⁺激活的Ca ₉ Bi（PO ₄）₇新型可调谐橙红色发射纳米磷光体。Ca ₉ Bi _{（1- x）} Sm _x（PO ₄）₇的晶体结构，相纯度，结构参数，光学带隙值，光致发光（PL）行为，能量转移，量子效率，寿命值和CIE色度指数对白色粉末状样品进行了连续分析。Ca ₉ Bi _0.88（PO ₄）_7的Rietveld细化：012Sm ³⁺样品导致成具有空间群R样品的三角晶结构3c中（161）与细化收敛至R _p  = 7.62％，R _WP  = 12.01％，和ꭓ ²  = 2.08。同时，发现Ca ₉ Bi _0.88 Sm _0.12（PO ₄）₇系统的平均微晶尺寸接近60 nm，这也得到了TEM图像的支持。Ca ₉ Bi _0.88 Sm _0.12（PO ₄）₇的能带隙（E _g）值估计为4.07 eV，Sm ³⁺离子之间的临界距离计算为21.09Å。确定Ca ₉ Bi（PO ₄）₇样品中Sm ³⁺离子的最佳浓度为12 mol％，并根据Dexter的理论和Huang的研究，得出Sm ³⁺离子之间能量转移的机理为偶极子-偶极子相互作用。在403 nm激发下，这些纳米磷光体在PL发射光谱中显示出三个带，分别在562 nm，600 nm和646 nm处达到峰值，对应于⁴ G _5/2 → ⁶ H _J转换（分别为J = 5 / 2、7 / 2和9/2）。随着Sm ³⁺离子浓度的增加，观察到寿命值从1.95 ms降低到1.39 ms 。采用Auzel的拟合功能后，辐射寿命得以延长；测量了非辐射速率，以及合成纳米磷的量子效率。发现Ca ₉ Bi _0.88（PO ₄）₇：0.12Sm ³⁺的CIE色坐标为（0.435，0.354 ），并且相应的量子效率估计为70.6％。我们目前的研究结果表明，Ca ₉ Bi（PO ₄）₇掺杂有Sm ³⁺ 离子可作为有前途的发射橙红色的纳米磷光体用于近紫外激发的WLED。