Gas-induced current decay of molybdenum field emitter arrays

Abstract

Articles you may be interested inDevelopment of a cold-cathode electron gun for cathode-ray tube using a Mo-tip field-emitter array Effect of O 2 on the electron emission characteristics of active molybdenum field emission cathode arrays Field emission displays can be seriously limited by current degradation of Mo field emitter arrays, primarily due to inadequate vacuum conditions inside their thin vacuum packages. Most lifetime studies describe the deleterious effects of short exposures to oxygenic gases on device performance. Here, we review experimental results on the emission characteristics of molybdenum field emitter arrays in a variety of gas ambients for extended periods. We find that even in inert gas, the emission current degrades rapidly, comparable to that observed in oxygenic gas ambients. Surprisingly, after exposure when the device is again operated under high vacuum conditions, various levels of current recovery can be observed. No evidence for ion sputter damage is observed. Existing degradation models do not provide an adequate explanation for this behavior. Rather, we suggest that these results point toward a model common for all gaseous ambients based on shallow implantation of ions into the field emitter tips. This creates a near surface layer that modifies the tunneling barrier, and thus subsequently the emission current. Support for this mechanism comes from several experimental observations. The implant degradation model is also consistent with devices that incorporate a field emitter ion pump process as a means to reduce pressure in the sealed vacuum package.

Homogeneity improvement of field emission beam from metallic nano-tip arrays by noble-gas conditioning

“…3,16 As one underlying mechanism of the emission homogeneity improvement, we consider that bombardment of emitters by noble-gas ions, that were generated by electron impact ionization near current-emitting tips, caused sputtering 6 or ion-implantation. 17 From the expected R tip -dependences for A FN ($NR tip 2 ) and B FN ($(R tip ) 0.5 ) with the FN exponent n of 2, the observed increase of A FN and B FN was compatible with the increase of R tip by sputtering-induced tip-blunting and removal of adsorbate and native oxide. Preferential sputtering of oxygen atoms from partially oxidized molybdenum emitter surface could also contribute to this.…”

Field Emission Properties of Low-Temperature, Hydrothermally Grown Tungsten Oxide

“…The substrate-to-anode distance was kept to 100 μm. Several conditioning runs were always conducted before the final stable and reproducible curves were recorded. , Each I – U curve is the average of at least three current–voltage scans, and each current value in a scan is the average of 10 measurements at that voltage.…”

Emission statistics for Si and HfC emitter arrays after residual gas exposure

“…2 However, more research has to be performed searching for emitter materials that are capable of high currents, are environmentally tolerant, and have stable emission. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] The purpose of this article is to assess the field emission properties of the HfC coated Si FEAs ͑hereinafter called HfC FEAs͒ as compared to ͑noncoated͒ Si FEAs, when subject to residual gases. [3][4][5][6][7][8][9][10] Several studies related to the emitter operation in gas ambient have been reported, concerning especially Spindt-type emitters.…”