Fls980 fluorimeter

¹H and ¹³C NMR spectra were recorded on a Bruker Avance 300, Bruker Avance III HD 400, or a Bruker Avance II⁺ 600 spectrometer. Chemical shifts (δ) are reported in parts per million (ppm), referenced to tetramethylsilane (0.00 ppm) as an internal standard for samples in CDCl₃, or to the solvent signal for samples in DMSO-d₆ (2.50 ppm). ¹³C NMR spectra were referenced to the respective solvent signals (CDCl₃ 77.16 ppm, CD₃OD 49.00 ppm and DMSO-d₆ 39.52 ppm). High-resolution mass spectra were acquired on a quadrupole orthogonal acceleration time-of-flight mass spectrometer (Synapt G2 HDMS, Waters, Milford, MA, USA). Samples were infused at 3 µL/min and spectra were obtained in positive ionization mode with a resolution of 15,000 (FWHM) using leucine enkephalin as lock mass. Melting points (not corrected) were determined using a Reichert Thermovar apparatus. Fluorescence spectra were recorded on a HORIBA Jobin Yvon Fluorolog FL3-22 fluorimeter and on an Edinburgh FLS980 fluorimeter. For the measurements at 77 K, the samples were transferred to a clean NMR tube and immersed in an accessory containing a liquid nitrogen dewar. Absolute quantum yields were determined with an integrating sphere and a 0.3% neutral density filter was used when recording the Rayleigh scatter.

Absorption spectra were taken with an Agilent 8453 UV-visible spectrometer. Steady-state photoluminescence measurements were recorded on an Edinburgh Instruments FLS980 fluorimeter. PLQE was measured using a 520 nm CW laser and the sample inside an integrating sphere, with detection via a fibre optic cable to an Andor iDus DU420A BVF Si detector. PLQE was calculated by the de Mello method to account for secondary absorption of scattered light^{50 (link)}. For photoluminescence measurements in a magnetic field, we used the CW 520 nm source and a pair of lenses to project the photoluminescence emitted to a solid angle of 0.1π onto an InGaAs detector, with the sample positioned in an electromagnet (GMW—Model 3470) with 3 cm distance between cylindrical poles. The magnetic field for a given voltage supplied to the electromagnet was measured with a gauss metre. Photostability measurements were performed using the same detector and excitation, with the transmitted 520 nm laser signal being measured over time, and converted to absorption using Absorbed photons = Incident photons−Transmitted photons.

Thin films of neat precursor, neat Ppy9 and their nanocomposite blends were prepared by spin-coating the solution onto fused silica substrates at 1200 rpm for 60 s. A solution of 20 mg Ppy9 in 1 mL of chloroform was used for spin-coating neat films of Ppy9. Films of neat precursor and nanocomposites (90:10 or 80:20 by precursor:polymer by weight) were prepared by dissolving 50 mg of materials (i.e., mass of precursor plus polymer total 50 mg) in 1 mL of chloroform. The films of neat precursor and nanocomposite blends were baked at temperatures in the range from 140 to 180 °C for 15 min or 30 min under low vacuum (~8 × 10² mbar).
The absorption of films was measured using a Cary 300 UV−Vis spectrophotometer and photoluminescence (PL) spectra were obtained using an Edinburgh Instruments FLS980 fluorimeter. The PL spectrum of the neat precursor without baking was measured using excitation at 380 nm, whereas the PL spectra of neat precursor baked at different temperatures were measured by exciting the films at their corresponding absorption edge. The PL spectra of neat Ppy9 and nanocomposite films were obtained by exciting the films at 330 nm. PLQY of all films was measured using a Hamamatsu integrating sphere C9920−02 luminescence measurement system at similar excitation wavelengths to PL.