Fls980 spectrometer

A quartz cuvette containing aqueous hybrid nanocomposites dispersion (2.5 mL, ≈5 mg mL⁻¹) was placed in a sample holder equipped with an external temperature controller (APCT‐2, Automatic Science Instrument CO., LTD.). A nonmode‐locked Ti: sapphire oscillator (710–920 nm, Maitai, Spectra Physics) (i.e., laser output is continuous) was utilized to generate 808 and 830 nm laser (FWHM ≈4 nm) to insure that the two lasers share the same optical path. The photoluminescence (PL) was collected by the lens and was recorded by a FLS 980 spectrometer (Edinburgh) with NIR detector (InGaAs PMT). For the signal acquisitions, the PL intensity at 1025/1057 nm was monitored with a slit of 3 nm; the PL full spectrum was recorded with a slit of 0.7 nm. The recording process of PL intensity at 1025/1057 nm was set to be less than 1 s, fast enough to avoid any side‐effect due to laser heating.

The CdSe/ZnS QDs for blue and green QDs and the CdSe/CdS/ZnS QDs for red QDs were synthesized in the laboratory. All QDs have CdSe–ZnS core-shell alloyed structures to enhance EL and show a PL quantum yield of >∼80%. The synthesis methods for the colloidal NCs are described in Supplementary Methods. Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS; VP AI 4083) was purchased from Clevios, and TFB (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl))diphenylamine)], SOL 2036) was purchased from Solaris. Anhydrous butanol, heptane and m-xylene were purchased from Sigma-Aldrich. Zinc oxide NCs for the ETL, PbS QDs and CuInSe QDs were synthesized in the laboratory (details in Supplementary Methods). Transmission electron microscopy images were obtained on a JEOL 2100F electron microscope. The absorption spectra were acquired on a CARY 5000E ultraviolet–visible–near-infrared spectrophotometer. PL and time-resolved fluorescence spectra were recorded on an FLS 980 spectrometer (Edinburgh Instruments). For PL, the QDs were excited with a steady-state xenon lamp, and the emitted photons were detected by a single-photon-counting photomultiplier. The valance band maximum of the layer materials was determined by the ultraviolet photoelectron spectroscopy (Thermo Fisher Scientific Co.) with a He discharge lamp (21.2 eV).

High-performance liquid chromatography (HPLC) was measured on a Waters 2487 (600E) equipment with a column of Poroshell 120 (EC-C18, 2.7 μm, 4.6 × 150 mm), using acetonitrile/water mixture (ratio = 9:1, v/v) with a flow rate of 1.0 mL/min. Nuclear magnetic resonance (NMR) spectra were carried out on a Bruker AVIII 400 MHz NMR spectrometer equipped with a Dual Probe, using deuterated chloroform (CDCl₃) as the solvent. High-resolution mass spectra (HRMS) were measured on a GCT premier CAB048 mass spectrometer manipulated in a GC-TOF module with chemical ionization (CI). Ultraviolet-visible (UV-Vis) spectra were collected on a Varian Cary 50 Conc UV-Visible Spectrophotometer with Peltier. Photoluminescence (PL) spectra and their lifetimes at room temperature and 77 K were recorded on an Edinburgh FLS980 Spectrometer. Absolute quantum yield (QY) was collected on a Hamamatsu Quantum Yield Spectrometer C11347 Quantaurus. Single-crystal X-ray diffraction (XRD) was carried out on a Rigaku Oxford Diffraction (SuperNova) with Atlas diffractometer (Cu Kα (λ = 1.54184 Å)). The single-crystal structures were solved with Olex2 software. Dynamic light scattering (DLS) measurements for the diameter of aggregates were measured on a Malvern Zetasizer Nano ZS equipment at room temperature. All digital photos of crystals and amorphous compounds were recorded on a Canon EOS 60D camera.

Emission measurements were carried out using thin film Cu₂O. For thin film preparation, a paste of 1 mg/1 mL (MeOH) was drop-cast on a 2 × 1 cm masked glass substrate and dried at 90 °C for 1 h (low temperature drying was used to avoid microstrutcure alteration).
The apparatus used was a FLS980 spectrometer (Edinburgh Instruments, 2 Bain Square Kirkton Campus, UK). A NIR PMT detector was used for wavelength scans beyond 850 nm.