华特·萧特基

-{H|zh-hans:肖特基; zh-hant:萧特基}-
华特·赫尔曼·萧特基（Walter Hermann Schottky，），德国物理学家。他在早期的电子与离子发射现象的理论发展上扮演着重要角色，于1919年发明帘栅极真空管（四极管），后来也在半导体元件、工程物理学、科技领域有许多重大贡献。现今萧特基二极体广泛用于每一台电脑、也在一些高频领域等有所应用。
学历.
1904年由德国柏林的毕业。1908年于柏林大学获得物理学士，1912年于柏林大学在普朗克在海因里希·鲁本斯指导下获得物理博士，论文名称是："Zur relativtheoretischen Energetik und Dynamik"。
经历.
1912-14年间在耶拿大学作博士后研究，1919-23年间在维尔茨堡大学讲学，1923-27年间担任罗斯托克大学理论物理教授。1914-19, 1927-58年间两度在西门子研究实验室（Siemens Research laboratories）工作。
主要科学成就.
回顾起来，萧特基最重要的科学成就可说是1914年发现的知名古典公式，一个点电荷q，与距离x的金属平面间的相互作用能，现今写成 -"q"2/16π"ε"0"x"
2/16π"ε"0"x", for the interaction energy between a point charge "q" and a "flat" metal surface, when the charge is at a distance "x" from the surface. Owing to the method of its derivation, this interaction is called the "image potential energy" (image PE). Schottky based his work on earlier work by Lord Kelvin relating to the image PE for a sphere. Schottky's image PE has become a standard component in simple models of the barrier to motion, "M"("x"), experienced by an electron on approaching a metal surface or a metal-semiconductor interface from the inside. (This "M"("x") is the quantity that appears when the one-dimensional, one-particle, Schrödinger equation is written in the form
Here, formula_2 is Planck's constant divided by 2π, and "m" is the electron mass.)
The image PE is usually combined with terms relating to an applied electric field "F" and to the height "h" (in the absence of any field) of the barrier. This leads to the following expression for the dependence of the barrier energy on distance "x", measured from the "electrical surface" of the metal, into the vacuum or into the semiconductor:
Here, "e" is the elementary positive charge, "ε"0 is the electric constant and "ε"r is the relative permittivity of the second medium (=1 for vacuum). In the case of a metal-semiconductor junction, this is called a Schottky barrier; in the case of the metal-vacuum interface, this is sometimes called a Schottky-Nordheim barrier. In many contexts, "h" has to be taken equal to the local work function "φ".
This Schottky-Nordheim barrier (SN barrier) has played in important role in the theories of thermionic emission and of field electron emission. Applying the field causes lowering of the barrier, and thus enhances the emission current in thermionic emission. This is called the "Schottky effect", and the resulting emission regime is called "Schottky emission". 
In 1923 Schottky suggested (incorrectly) that the experimental phenomenon then called autoelectronic emission and now called field electron emission resulted when the barrier was pulled down to zero. In fact, the effect is due to wave-mechanical tunneling, as shown by Fowler and Nordheim in 1928. But the SN barrier has now become the standard model for the tunneling barrier.
Later, in the context of semiconductor devices, it was suggested that a similar barrier should exist at the junction of a metal and a semiconductor. Such barriers are now widely known as Schottky barriers, and considerations apply to the transfer of electrons across them that are analogous to the older considerations of how electrons are emitted from a metal into vacuum. (Basically, several emission regimes exist, for different combinations of field and temperature. The different regimes are governed by different approximate formulae.)
When the whole behaviour of such interfaces is examined, it is found that they can act (asymmetrically) as a special form of electronic diode, now called a Schottky diode . In this context, the metal-semiconductor junction is known as a "Schottky (rectifying) contact'". 
Schottky's contributions, in surface science/emission electronics and in semiconductor-device theory, now form a significant and pervasive part of the background to these subjects. It could possibly be argued that - perhaps because they are in the area of technical physics - they are not as generally well recognized as they ought to be.
获奖.
因发现热电子发射的散粒效应（萧特基称它是Schrot effect），也就是在高真空放电管中的自发性的电流变化，以及发明帘栅极真空管与接收无线电讯号的超外差方式，于1936年获得伦敦皇家学会休斯奖章。
为了表扬他在理解许多物理现象上所做的开创性工作，并促成许多重要的技术应用，例如真空管放大器、半导体等方面的贡献，于1964年获得德国技术科学最高荣誉：。
个人生活与家庭.
父亲是数学家（1851–1935）。 妻子是Elizabeth，育有一女两子。 华特·萧特基的父亲于1882年被聘任为苏黎世大学的数学教授，四年后华特出生，1892年又接受马尔堡大学聘任而移居德国。
纪念.
以他的名字来命名纪念的事物有：德国、，以及萧特基能障、萧特基二极体。