We investigated the influence of the surface state of diamond layers on the characteristics of the photoemission induced by 4.7 eV photons. A series of diamond samples grown by CVD under slightly different conditions have been analysed. Polycrystalline diamond layers with nanoscale graphitic patches embedded at the grain boundaries are found to exhibit unusually high efficiency of electron photoemission. The photoemitting properties of the different samples are rationalized by considering the electron emission process located at the a-C/diamond/vacuum triple border and the quantum efficiency (Q.E). governed by the ratio of amorphous sp 2-C to crystalline sp 3-C. At 4.7 eV values of quantum efficiency up to 1.5 × 10 -5 have been measured and the trends of the experimental Q vs J curves indicate that photoemission occurred mainly under one-photon regimes.
Photoemission from nano-structured a-C/diamond layers irradiated byintense Nd:YAG laser harmonics / S., Orlanducci; A., Fiori; M. L., Terranova; F., Tazzioli; C., Vicario; S., Cialdi; Rossi, Marco. - STAMPA. - 5838:(2005), pp. 216-223. (Intervento presentato al convegno Nanotechnology II tenutosi a Seville nel 9 May 2005 through 11 May 2005) [10.1117/12.609584].
Photoemission from nano-structured a-C/diamond layers irradiated byintense Nd:YAG laser harmonics
ROSSI, Marco
2005
Abstract
We investigated the influence of the surface state of diamond layers on the characteristics of the photoemission induced by 4.7 eV photons. A series of diamond samples grown by CVD under slightly different conditions have been analysed. Polycrystalline diamond layers with nanoscale graphitic patches embedded at the grain boundaries are found to exhibit unusually high efficiency of electron photoemission. The photoemitting properties of the different samples are rationalized by considering the electron emission process located at the a-C/diamond/vacuum triple border and the quantum efficiency (Q.E). governed by the ratio of amorphous sp 2-C to crystalline sp 3-C. At 4.7 eV values of quantum efficiency up to 1.5 × 10 -5 have been measured and the trends of the experimental Q vs J curves indicate that photoemission occurred mainly under one-photon regimes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
