Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
702573 | Diamond and Related Materials | 2011 | 5 Pages |
We successfully observed electron emission from hydrogenated diamond p–i–n junction diodes with negative electron affinity during room temperature operation. The emissions started when the applied bias voltage produced flat-band conditions, where the capacitance–voltage characteristics showed carrier injection in the i-layer. In this low current injection region, the electron emission efficiency (η) of the p–i–n junction diodes (p is top layer) was about 5 × 10− 5, while that of the n–i–p diodes (n is top layer) was about 10− 8. With increasing diode current, both diodes showed an increase in η and a nonlinear increase in emission current. In the high current injection region with high diode current of 5–50 mA, both diodes had an emission current of almost 10 μA, where η of a p–i–n junction diode was 0.18%, while that of a n–i–p junction diode was 0.02%.Note that η, which corresponds to the electron emission mechanism, depended on the diode current level.
Research highlights► Electron emission of 8.8-10 μA from diamond p-i-n junction diodes with negative electron affinity was obtained. ► The top layers facing to the collector electrodes were a p layer or an n layer. ► In low injection region, a p-top diode exhibited 5000 times larger efficiencies (η) than that of an n-top diode. ► However, increasing of the diode current increased both η’s, and closed to each. ► Note that η, which corresponds to the electron emission mechanism, depended on the diode current level.