Tecnai g2 t20 microscope

The CH₃NH₃PbI₃ microribbons grown on substrates were directly characterized with a cold field emission scanning electron microscope (Hitachi S4800, operated at 2.0 kV, 10 μA) and an X-ray diffractometer (D/MAX-PC 2500, Rigaku, with Cu Ka radiation at λ = 0.154 nm). A Bruker D8 Discover diffractometer with a general area detector diffraction system (GADDS) as a 2D detector was applied for 2D wide angle X-ray diffraction (WAXD) measurements. The calibration was done with silicon powder and silver benzoate. The TEM specimen was prepared by rubbing the grid with the microribbon arrays. The high-resolution TEM characterization was carried out on a FEI Tecnai G2 T20 microscope. A Dimension Icon SPM (Bruker, Santa Barbara, CA, USA) was used to perform the AFM topographic measurements of the CH₃NH₃PbI₃ arrays. The photo response performance of the devices was studied under ambient conditions using a tungsten lamp with a power density ranging from 0 to 15 mW/cm².

TEM was performed to identify the intracellular distribution of NPs. After exposure to the NPs, cells were fixed for 2 h with a solution containing 2.5% glutaraldehyde, 2% parafolmadeide, and phosphate buffer. After fixing, the samples were washed three times with 0.1 M phosphate for 30 min. Post-fixation was done with Osmium tetroxide and 0.2 M phosphate buffer for 45 min and washed again. Then, the samples were dehydrated with acetone and soaked in resin for 24 h. The cells already embedded in pure resin were left in the oven at a constant temperature of 60  ${}^{\circ }$ C for 72 h. Finally, the samples were cut by ultramicrotomy into 100 nm slices and deposited in TEM grids for imaging in a FEI Tecnai G2 T20 microscope.