arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1710.03992cond-mat.mes-hall
收藏

纳米尖场发射的隧穿势

The tunneling potential for field emission from nanotips

Debabrata Biswas, Rajasree Ramachandran, Gaurav Singh

摘要:

在场发射的准平面近似中,由于外部静电场$E_0$产生的势能表示为$-e γE_0 Δs$,其中$Δs$是距发射位点的垂直距离,而$γ$是发射体表面上的局部场增强因子。我们表明,对于弯曲的发射极尖端,电流密度可以准确地计算,如果条款涉及$(Δs/R_2)^2$和$(Δs/R_2)^3$被纳入潜在的$R_2$是第二(较小)的原则曲率半径。半椭球和双曲面发射体的结果是建立解析,它被发现,对于急剧弯曲的发射体,膨胀系数是相等的,并符合一个球体。扩展似乎是适用于通用的发射器,如数字所示的发射器与圆锥形基地和方形尖端。对于局部场强为$5$ V/nm或更高的$R_a \gtrapprox 2$ nm,电势中的校正项是足够的。该结果也可以用于纳米尖端发射器阵列,甚至是随机放置的一堆尖锐发射器。

英文摘要:

In the quasi-planar approximation of field emission, the potential energy due to an external electrostatic field $E_0$ is expressed as $-e γE_0 Δs$ where $Δs$ is the perpendicular distance from the emission site and $γ$ is the local field enhancement factor on the surface of the emitter. We show that for curved emitter tips, the current density can be accurately computed if terms involving $(Δs/R_2)^2$ and $(Δs/R_2)^3$ are incorporated in the potential where $R_2$ is the second (smaller) principle radius of curvature. The result is established analytically for the hemiellipsoid and hyperboloid emitters and it is found that for sharply curved emitters, the expansion coefficients are equal and coincide with that of a sphere. The expansion seems to be applicable to generic emitters as demonstrated numerically for an emitter with a conical base and quadratic tip. The correction terms in the potential are adequate for $R_a \gtrapprox 2$ nm for local field strengths of $5$ V/nm or higher. The result can also be used for nano-tipped emitter arrays or even a randomly placed bunch of sharp emitters.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑