Fig. 2: Structures and properties of BN-O and BN.

a Chemical structures of BN-O and BN. b Absorption and (c) photoluminescence (PL) spectra of BN-O and BN in DMSO. d HOMO and LUMO electron cloud distribution and energy levels of BN-O and BN. e PL intensity of DCF at 525 nm in the presence of BN-O or BN under the irradiation of 730 nm NIR light (1.0 W cm⁻²) for different times. I₀ and I stand for the PL intensity of DCF at 525 nm before and after 730 nm NIR light irradiation. f PL spectra of DHR 123 (10 µM) in the presence of BN under 730 light (1.0 W cm⁻²) irradiation for different times. g Temperature changes of BN-O and BN upon 730 nm light (1.0 W cm⁻²) irradiation for different times. h Temperature changes of BN under the irradiation of 730 nm light with different power intensities. i Temperature changes of BN with five circles of 730 nm laser on-off processes. j PA intensity of BN-O and BN at different wavelengths. k PA profiles and (l) corresponding PA intensity of various concentrations of BN at 780 nm. Data are presented as mean ± SD (n = 3 independent samples). m PA intensity of BN under PA excitation for different durations. n Schematic illustration of the photophysical energy transformation processes and photophysical properties of BN. For (b‒l), experiment was repeated three times independently with similar results. Source data are provided as a Source Data file.