Lambda 1050 spectrophotometer

The ferroelectric hysteresis loops were obtained using the Radiant Technologies Precision LC II Ferroelectric Tester. The 2D ferroelectric domain phase mapping characterizations were aquired through Piezoelectric Force Microscopy (PFM) using a Bruker Dimension Icon with SCM-PIT probes. The magnetic hysteresis loops were measured by the Quantum Design MPMS-3 SQUID magnetometer in vibrating sample magnetometry (VSM) mode. The ellipsometry measurements were performed using the J.A. Woollam RC2 spectroscopic ellipsometer. Various oscillators models were constructed to fit this data with the Mean Square Error (MSE) always below 5. Optical transmittance characterization was completed using the PerkinElmer LAMBDA 1050 spectrophotometer.

Absorption spectra were recorded with a PerkinElmer LAMBDA 1050 spectrophotometer equipped with an integrating sphere to account for reflected and transmitted light. PDS measurements were acquired on a custom-built setup by monitoring the deflection of a fixed wavelength (670 nm) laser probe beam following absorption of each monochromatic pump wavelength by a thin film immersed in an inert liquid FC-72 Fluorinert (3M Company). PL quantum yield measurements were taken by mounting perovskite films or encapsulated device stacks in an integrating sphere and photoexciting with a 532-nm continuous-wave laser. The laser and the emission signals were measured and quantified using a calibrated Andor iDus DU490A InGaAs detector for the determination of PLQE.

The stability of E-MoS₂, ZnO and the hybrid ZnO-MoS₂ nanocomposite was compared by measuring its zeta potential using a zetasizer nano ZS (Malvern Panalytical Ltd.,Worcestershire, UK). ZnO and the as-prepared dried samples of the hybrid ZnO-MoS₂ were prepared using deionised water (pH 7.6) at a concentration of 3 mg/mL, and the dispersion of E-MoS₂ was centrifuged and later re-dispersed in deionised water at a similar concentration. All measurements were performed in triplicates to determine the average zeta potential. Raman spectra of E-MoS₂ and the hybrid ZnO-MoS₂ photocatalyst were collected by means of a non-resonant 532 nm cw laser. The full-spectrum was recorded while placing the samples on a standard XY motorised stage and a coupled microscope objective (20× with 3 μm laser spot size) helped in scanning and collecting the back-scattered light using a grating spectrometer. Optical analysis was performed using UV–vis spectroscopy (Perkin-Elmer lambda 1050 spectrophotometer, Waltham, MA, USA) to measure the band gap energy of the prepared photocatalyst by means of the well-known Tauc relation, Equation (1).

where h refers to the Plank constant, ν is the incident of light frequency, A is the absorbance, E_g is the bandgap and n equals to ½, which refers to the direct band gap energy of the E-MoS₂ dispersion.