Semiconductor boron-doped CVD diamond lms were prepared on Si substrates by the hot lament technique. The surface morphology analysis by SEM presented continuous and well faceted lms.The samples were grown with di erent boron concentrations by controlling the B=C ratio in the feeding gas. Raman results showed a drastic change of diamond lms for di erent doping levels. The characteristic line at 1332 cm ,1 decreases and shifts to lower energy as a function of the lm resistivity. I t w as also observed a broad peak around 1220 cm ,1 caused by the incorporation of boron in the diamond lattice. Photocurrent-voltage behaviour of undoped and boron-doped diamond electrodes was investigated in dark and UV visible irradiation. The voltammograms showed that doped electrodes illuminated with a xenon lamp exhibited currents signi catively higher because of the increased conductivity. F or undoped electrodes it was observed a small photocurrent for anodic and cathodic polarization in the order of A for the potential range of +1.0 V and -1.0 V Ag=AgCl , for 1.0 M KCl. Mott-Schottky plots studied the interfacial processes at diamondelectrolyte junction. The atband potential Ufb was found between 0.6 and 0.8 V Ag=AgCl which v aries with the presence of sp 2 -type carbon as an impurity. F rom the curve slope the acceptor concentrations were found in the range of 10 18 and 10 21 cm ,3 . These values agree with the estimated concentration obtained by Raman measurements. I IntroductionThe evolution of research on semiconductor diamond has shown promising results with doping process during CVD growth. Due to its easy production and high stability, there is a great interest in studying the development of boron doped diamond leading to the application of these lms as electrode for, photoelectrochemical PEC cells, sensors, etc 1-3 .The standard methods used for CVD boron-doped diamond were initially thermal di usion 4,5 and ion implantation 6,7 . These processes were made ex situ", after the lm growth. The main advantage is the no-contamination of the growth reactor. Martin et al. 4 have obtained highly doped lms, using in situ" process from a solid source of boron inside of the reactor. Better results that evidenced more homogeneous lms were observed. CVD-grown polycrystalline diamond lms, depending on growth conditions, can have a wide spectrum of electrophysical properties. Their properties depend on the concentrations of defects in diamond grains, on the volume fraction of the nondiamond intergrain boundary phase, and on its nature. Okano et al 8 have proposed the boron doping during the CVD growth process using the hot lament reactor introducing B 2 O 3 dissolved in methanol-acetona mixture, that works as a carbon source for diamond growth. Their results showed lms with linear relation between the doping levels and boron concentration.Pleskov et al. 9 have studied, for the rst time, the electrochemical and PEC behaviour of diamond electrodes. Tenne and Swain 10,11 have made cyclic voltammograms in the presence of redox couples. Sa...
A nitriding process based on two distinct nitrogen glow discharge modes, with sample temperatures ranging from 380 0 C to 480 0 C, was employed to treat the surface of austenitic stainless steel (SS 304). The temperature is controlled exclusively by switching the operation conditions of the discharges. First mode of operation is the conventional one, named cathodic, which runs at higher pressure values (1 mbar) in comparison to the second mode, named anodic, which runs at the pressure range of 10 −3 − 10 −2 mbar. Cathodic mode is used to quickly heat the sample holder, by the high ion flux. On the other hand, in the anodic mode, due to the lower operation pressure, higher effective ion acceleration takes place, which allows deeper ion implantation into the sample surface. This hybrid process was thoroughly explored regarding the duty cycle and conditions of operation, to achieve optimal performance of the treatments, which led to the attainment of surface hardness for samples of AISI SS 304 as high as 20 GPa and improvements including higher elastic modulus and resistance against corrosion. Detailed comparison among samples treated by this process with others treated by conventional method was done using nanoindentation, Auger Electron Spectroscopy (AES) and corrosion resistance testing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.