On the effect of laser irradiation and heat treatment on the structure and field-emission properties of carbon nanowalls

Carbon nanowalls in field emission cathodes

“…that impair the emission characteristics of the autocathodes [4,15]. To recover the emission properties of autocathodes that had passed preliminary tests, they are annealing in vacuum or in an inert gas DOI: 10.15222/TKEA2017.6.34 ISSN 2225-5818 atmosphere at a temperature of about 720 K [6]. Autocathodes that had not passed preliminary tests (even without vacuum breakdown), as a rule are not further used.…”

“…The structure and concentration of crystalline and X-ray amorphous phases depend on the conditions for carbon materials formation and affect their emission properties. The problems of using CNW in autocathodes are associated with the instability of emission parameters (magnitude and density of the cathode current, as well as the degree of electrical current uniformity over the cathode area) due to changes in composition and structure during testing and operation [4,6,8].Before being placed into electrovacuum devices and soldered, autocathodes are always preliminaryly tested in a vacuum chamber for compatibility with the parametres of the device. In some cases, preliminary tests are carried out to achieve such required parameters as autoemission current and its stability in time.…”

“…The structure and concentration of crystalline and X-ray amorphous phases depend on the conditions for carbon materials formation and affect their emission properties. The problems of using CNW in autocathodes are associated with the instability of emission parameters (magnitude and density of the cathode current, as well as the degree of electrical current uniformity over the cathode area) due to changes in composition and structure during testing and operation [4,6,8].…”

“…The layers of carbon materials formed by plasma methods, including CNW, are as a rule multiphase layers [6][7][8]. The structure and concentration of crystalline and X-ray amorphous phases depend on the conditions for carbon materials formation and affect their emission properties.…”

“…Autocathodes are used in the development of X-ray tubes, microwave devices, electron guns for exciting lasers, cathodoluminescent lighting devices, flat displays and other devices [1][2][3][4][5]. The most promising for the creation of autocathodes with a low electron emission barrier are the so-called carbon nanowalls (CNW) -layers of a plate-like carbon material with a predominant orientation of the plates perpendicular to the substrate [1][2][3].The layers of carbon materials formed by plasma methods, including CNW, are as a rule multiphase layers [6][7][8]. The structure and concentration of crystalline and X-ray amorphous phases depend on the conditions for carbon materials formation and affect their emission properties.…”