Compound characterization data

INPs from the supernatant fraction
XRD	broad diffraction peak at 2θ ≈ 29°, corresponding to the Sb0 (012) plane
Raman spectroscopy	peak at 148 cm⁻¹; deconvoluted Ag and Eg Sb-Sb stretching modes at 148 cm⁻¹ and 112 cm⁻¹
XRF	Sb-dominant (Sb, 59.1 mol%), with 30.8 mol% (In) corresponding to. 3.5 nm NCs (In and Sb)
SAXS	average diameter of 4.2 nm and a polydispersity of approx. 38 %, (FWHM= 1.49 nm)

INPs from the precipitate fraction
XRD	lattice planes (101), (002), and (110), with an average size of 50 nm (calculated by the Scherrer equation)
XRF	In, 58.86 mol%; Sb, 9.36 mol%

Products formed at each temperature
XRD, RT–140 °C, supernatant	~ 4 nm Sb NPs, with broad peaks around 29°
XRD, RT–140 °C, precipitate	unreacted In0 INPs, as confirmed by the XRD peaks (101), (002), (110), along side byproducts LiCl and In2O3
Absorption spectra, RT–140 °C	remain featureless
XRD, 140–160 °C	InSb (111), (220), and (311) peaks emerge, though residual Sb persists in the supernatant
Absorption spectra, 140–160 °C	a broad excitonic peak
XRD, above 160 °C	the Sb0 (012) peak disappears, while InSb peaks intensify
Absorption spectra, above 160 °C	develop sharp excitonic features

InSb quantum dots
XRD, Approach 2, 300 °C	pure zinc blende structure
Absorption spectra, Approach 2, 140–300 °C	broad excitonic features with a progressive redshift and increased size dispersion
Absorption spectra, InI3/SbI3-derived QDs	1170 nm
Absorption spectra, SH/Sb ratio from 6 to 10 (In:Sb = 2:1)	1720 nm (8.5 nm) to 1078 nm (6.5 nm)
Absorption spectra, In/Sb ratio from 2.0 to 5.0	red shift evolution from 1225 nm (6.9 nm) to 1730 nm (8.6 nm)
Absorption spectra, reaction time from 15 to 180 min at 300 °C (In:Sb:SH = 2:1:9)	redshift of the exitonic peak from 1120 (6.7 nm) to 1750 nm (8.7 nm)
Absorption spectra, In:Sb:SH = 3:1:9, reaction time up to 150 min, 300 °C	shifted from 1470 nm (7.8 nm) to ~2200 nm (10.4 nm)
XRD	pure cubic zinc-blende phase, characterized by distinct (111), (220), and (311) lattice planes
Rietveld refinement of the XRD pattern, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	pure zinc-blende structure with high crystallinity
HR-STEM, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	(111) and (220) planes; lattice spacings of 3.7 Å and 2.3 Å, respectively
Raman spectroscopy, LO, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	180.5 cm⁻¹
EDX, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	In-to-Sb ratio of 1.06; Cl, 13.32 mol%
XRF, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	In-to-Sb ratio of 0.90; Cl, 13.63 mol%
XPS, In 3d, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	peaks at 444 and 451 eV binding energies; atomic fraction of In, 7.2 %; Sb, 6.1 %
XPS, Cl, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	0.4 %
XPS signals, absorbance at 1380 nm, size 7.4 ± 0.4 nm, obtained at 300 °C	In2O3 and Sb2Ox (x = 3, 5)
Size-dependent PL, sizes 6.8, 7.4, 7.9, and 9.6 nm	emission spanning from 1455 nm to 2020 nm as the NCs size increases
PL linewidth with QD size	FWHM of 288 nm 175 nm with increasing size
Temperature-dependent PL, first excitonic wavelength at 2000 nm, PMMA film	PL intensity decreases by an order of magnitude from 4 K to 300 K; Ea1 ≈ 7.25 meV at T < 75 K; Ea2 ≈ 56.25 meV at T > 100 K
PL FWHM, first excitonic wavelength at 2000 nm, PMMA film	267.0 nm at 4 K; 290 nm at 300 K
PL FWHM, first excitonic wavelength at 2000 nm, tetrachloroethylene solution, room temperature	175 nm
Power-dependent PL, first excitonic wavelength at 2000 nm, PMMA film, 4 K	excitation power (0.65–18.00 mW); emission peak remained stable at ~1980 nm; k = 0.84 (R² = 0.98)
TRPL, tetrachloroethylene solution, room temperature, excitonic peak at 2000 nm	τ1 ≈ 0.12 ns, accounting for 82.7 % of the recombination amplitude; τ2 ≈ 0.8 ns
Absorbance spectra collected over 4 months under an inert atmosphere	60 nm blue shift