X pert pro mrd system

Materials growth was performed in an Aixtron MOVPE CCS 3 × 2″ system on a 2 inch (0001) sapphire substrate. Triethylboron (TEB), Trimethylgallium (TMGa), Trimethylaluminum (TMAl) and Ammonia (NH₃), were used as B, Ga, Al and N sources respectively. First, an h-BN layer (3–5 nm) was grown on the sapphire substrate at 1300 °C. Then, a nucleation AlGaN layer (250 nm) with an Al mole fraction of 14% was grown at 1100 °C. We subsequently grew an AlGaN/GaN heterostructure consisting of a 1-µm-thick GaN buffer layer and a 25-nm-thick AlGaN barrier layer with an Al composition of 25%, which was confirmed by XRD measurements. Finally, a 3 nm GaN cap layer was grown. High resolution X-ray diffraction (HRXRD) scans were done in Panalytical X’pert Pro MRD system with Cu Kα radiation.

High-resolution X-ray diffraction (HR-XRD) scans were done in Panalytical X’pert Pro MRD system with Cu Kα radiation. Raman shift spectra were measured by LabRam HR EVOLUTION Raman spectroscopy with laser excitation at 532 nm. For the crystallography studies, high-resolution transmission electron microscopy (HRTEM) characterizations were performed on Titan Themis microscope working at 200 kV and equipped with a Ceta 16 M camera. The cross-sectional sample was prepared using focused ion beam (FIB) thinning and ionmilling. 100 nm-thick carbon was deposited before FIB to protect the surface. Absorption measurements were done by a LAMDA 900 spectrometer. Emission properties were studied by cathodoluminescence (CL) at 77 K and photoluminescence (PL) mapping at room temperature.

The morphologies of the catalysts were examined by a field scanning electron microscopy (SEM, Hitachi S-4800, Japan). The transmission electron microscopy (TEM) of the samples was investigated with a TECNAI G² F-20 microscope operating at 200 kV. The energy dispersive X-ray (EDX) analysis was conducted with a Horiba EMAX X-act energy dispersive spectroscope that was attached to the S-4800 system. The X–ray diffraction (XRD) measurements were performed on a PANalytical X’ Pert PRO MRD system with Cu K_α radiation (λ = 1.54056 Å) operated at 40 kV and 30 mA. The X-ray Fluorescence (XRF) detections were performed on a Rigaku ZSX Primus II Spectrometer equipped with Al 25 optical filter. The Raman spectra were recorded on a Renishaw InviaPlus Raman microscope using a 633 nm argon ion laser. All of the measurements were carried out at room temperature.