Lambda 900 spectrometer

Electrical current–voltage, I–V, measurements were performed by the Keithley617 Programmable Electrometer. The voltage source has been used in conjunction with the electrometer section, to apply to the samples voltages from −2 to +2 V, where GaS has ohmic behavior. Contacts were made using silver. Current was measured in the dark whereas photoresponse was investigated in the visible range under a 100 mW·cm⁻² AM1.5 spectrum lamp and in the UV range using a 405-nm laser of 250 mW cm⁻² as source.
UV–Vis transmittance spectra were measured on the same glass samples with a Perkin Elmer Lambda 900 spectrometer.

SEM imaging: cross-sectional SEMs of typical devices were acquired using a Hitachi SU-8230 apparatus after cleaving the samples with a diamond scriber. Absorption spectroscopy was performed with a Perkin Elmer Lambda 900 spectrometer with an integrating sphere attachment. Total absorption was calculated from transmission and reflection as A=1−R−T.

UV-vis absorption spectra were obtained with a Perkin Elmer Lambda 900 spectrometer. PL spectra were obtained with a SPEX 270 M monochromator equipped with a N₂ cooled CCD by exciting with a monochromated 450 W Xe lamp and corrected for the instrument response. PL QY of solutions were obtained by using quinine sulfate as reference. PL QY of solid powders were measured with a home-made integrating sphere according to the procedure reported elsewhere.^{37 (link)}

Steady-state electronic absorption and UV-visible emission measurements were carried out with 1.0 × 1.0 cm quartz cuvettes equipped with Kontes stopcocks. Electronic absorption spectra at room temperature were recorded using a Perkin-Elmer Lambda 900 spectrometer in THF solution.
Fluorescence measurements were made on a SPEX Fluoromax-2 spectrofluorometer in the UV-visible region in THF solution. The compounds were irradiated into their MLCT absorption bands. Emission measurements in the near-infrared region were performed in J. Young NMR tubes at room temperature and 77 K in 2-methyl THF. Spectra were recorded on a home-built instrument equipped with a germanium detector. Samples were irradiated into their MLCT bands. On the NIR setup, this was done with either 405 nm (1A–4A) or 658 nm (1B, 2B). Samples were prepared with an absorbance of <0.3.

The size distribution of the FCDs was measured by a Tecnai G2 F20 TEM characterization (FEI, Hillsboro, OR, USA). Absorption spectra were determined on a Perkin-Elmer-Lambda 900 spectrometer (PerkinElmer, Waltham, MA, USA). FL spectra were measured on a FluoroMax-P spectrophotometer (Horiba Jobin Yvon, Paris, France). Infrared spectra (IR) were measured on a Prestige IR21 FTIR spectrometer (Shimadzu, Kyoto, Japan).

NMR spectra were recorded at room temperature on a 500 MHz Bruker AVANCE III and referenced internally using the residual solvent proton and carbon peaks. EPR spectra were recorded on a Bruker EMX-10 EPR at room temperature in a solution of EtOH/MeOH (4:1). UV–vis absorption spectra were recorded in acetonitrile solutions in screw-capped 1 cm quartz cuvettes using a Perkin Elmer Lambda 900 spectrometer (PerkinElmer, Inc., Waltham, MA, USA). Cyclic voltammetry (CV) measurements were performed with a CH Instruments potentiostat. Samples were dissolved in acetonitrile with 0.1 M TBAPF₆ as a supporting electrolyte or in phosphate buffer for aqueous experiments. A 3 mm diameter glassy carbon working electrode and a platinum wire counter electrode were used. For non-aqueous experiments, a silver wire pseudoreference electrode was used, and the potential was internally referenced to Fc/Fc⁺. For aqueous experiments, an aqueous silver/silver chloride reference electrode from CH Instruments was used. O₂ formation was analyzed using a Vernier Optical Dissolved Oxygen probe. The bulk purity for metal complexes and ligands is established using elemental analysis performed in a UNICUBE Elemental analyzer.