Electron Emission from a Diamond (111) p–i–n⁺Junction Diode with Negative Electron Affinity during Room Temperature Operation

Abstract

We successfully observed electron emission from hydrogenated diamond (111) p–i–n+ junction diodes with negative electron affinity during room temperature operation. A heavily doped layer and p–i–n junction structure, rather than a p–n junction structure, play important roles in obtaining high diode and emission currents. The emission started when the applied bias voltage was equal to the expected built-in potential, and the emission current reached 8.8 µA during the room temperature operation. In this high current region, we observed an increase in quantum efficiency – a nonlinear increase in emission current.

Electron emission from diamond p–i–n junction diode with heavily P‐doped n+ top layer

“…The electron emission was not observed before hydrogenation, which was always the same results in all the previous diodes 16, 20. These results indicate electron emission owing to NEA.…”

“…As mentioned above, η once dropped in two orders of magnitude just above V f = V bi . According to Koizumi's results and our previous results, such a significant drop of η just above V f = V bi was not observed with diodes using p top layer structures 8, 20. In this region, the excess forward voltage V f − V bi is induced electric field in some part of the diodes, which resulted in the drop of η in the low injection region with the current diodes using n + / n top layers structure.…”

“…Above V f = 16.4 V, I d reached to the limited level of 80 mA (235 A/cm 2 ) for this measurement system. Here the η increased again, which means that the I e increased with increase of I d nonlinearly 20. Finally I e reached to 78 µA with the efficiency η = 0.1% during RT operation.…”

Evidence for phase separation of ethanol-water mixtures at the hydrogen terminated nanocrystalline diamond surface

“…Ranging from surfaceconductive field-effect transistors, 3,4 thermionic emission devices, [5][6][7] to the starting point for many functionalisation experiments leading to novel biosensor concepts. [8][9][10] In many of these situations, the diamond surface is in contact with a fluid.…”

Electron field emission from undoped polycrystalline diamond particles synthesized by microwave-plasma chemical vapor deposition

“…Thin films of diamond 1 and boron nitride 2,3 are promising candidates for use as such emitters because of their negative electron affinity (NEA) 4 that is attained by hydrogen termination on the surface. 10 Although the structures of the junction-diodebased emitters are more complex than those of the conventional monopolar emitters with homogeneous electronic characteristics inside the tip, their use has made it possible to obtain turn-on voltages of less than 10 V. 11,12 All of the field emitters mentioned require the use of intricate doping techniques given that diamond is intrinsically dielectric. On the other hand, the biasing of pn junctions in semiconductors has also been demonstrated to produce electron emission.…”