Helios g4 cx microscope

The SEM analysis was undertaken with
a Hitachi SU-70 scanning electron microscope. The transmission electron
microscopy images of the as-synthesized NRs and device cross-section
were characterized using a JEOL JEM-2100F transmission electron microscope
(TEM) with 200 keV electron beam energy; the device cross sections
were characterized by an FEI Helios G4 CX microscope operated at 5–10
kV. The absorption spectra of the nanocrystals were measured using
a Cary Series UV–vis–NIR spectrophotometer. The room
temperature PL spectrum of the NRs in toluene was collected by an
Ocean Optics 2000+ spectrometer under an excitation wavelength of
405 nm. The absolute photoluminescence quantum yield of the NR film
was measured by using an integrating sphere coupled with an Ocean
Optics Flame spectrometer.
The current–voltage–luminance
characteristics were measured using a Keithley 2602B source, Thorlabs
4P3 integrating sphere, and an HMO3004 oscilloscope coupled to a calibrated
PDA200C photodiode amplifier from Thorlabs. The EQE was calculated
as the ratio of the photon flux and driving current of the device.
The electroluminescence (EL) spectra of the devices were obtained
by using an Ocean Optics HR4000+ spectrometer. Time-resolved PL (TRPL)
measurements were carried out with a PicoQuant MicroTime 200 STED
system, utilizing a 405 nm excitation light source.

To investigate the membrane structure and pore size, scanning electron microscopy (SEM) images of the upper side of the Anodisc^™ membranes were taken with a Helios G4 CX microscope (FEI, Hillsboro, OR, USA) and an Everhart–Thornley detector. Before investigation, small pieces were broken out of the membranes and sputtered with 6 nm platinum (working distance 50 mm) in a high-vacuum coater (Leica EM ACE600, Leica Microsystems GmbH, Wetzlar, Germany). The images were taken with a voltage of 10 kV at a distance of 4 to 6 mm and different magnifications.
The size of all membrane pores of one representative image (per membrane) were measured and averaged with the software ImageJ. Images of 25,000× magnification (200 nm and 100 nm Anodisc^™) and 120,000× magnification (20 nm Anodisc^™) were used for this analysis. The software calculated the maximum Feret diameter (Feret_max) measuring the maximum distance between two parallel tangents applied to the pore (at any angle).