英语翻译Thus the observation of two bias regimes with different overall capacitance can be explained by a drastic drop of the resistance of the NPB layer at the critical voltage V0.This means that at the voltage V0 (which is still below Vbi) the
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英语翻译Thus the observation of two bias regimes with different overall capacitance can be explained by a drastic drop of the resistance of the NPB layer at the critical voltage V0.This means that at the voltage V0 (which is still below Vbi) the
英语翻译
Thus the observation of two bias regimes with different overall capacitance can be explained by a drastic drop of the resistance of the NPB layer at the critical voltage V0.This means that at the voltage V0 (which is still below Vbi) the NPB layer must have reached the flat-band condition so that holes can be injected into NPB from the ITO anode.However,this in turn implies that the applied voltage now completely drops at the Alq layer.Therefore the internal electric field is zero in the NPB layer and equal to (V0−Vbi)/dAlq in the Alq layer.Following from Poisson's law such a discontinuity ΔF of the electric field at an interface can only be caused by an interfacial charge Q0
If this effect is an intrinsic property of the NPB/Alq interface,then the magnitude of Q0 should not depend on external parameters,in particular not on the thickness of the organic layers.This in turn implies that the transition voltage V0 should display a linear dependence on the Alq thickness,which is indeed seen in Fig.25.From the slope ΔF=−0.35 MV/cm one directly obtains the magnitude of the interfacial charge density as σ0=Q0/qA=ΔF 0/q=−6.8×1011 cm−2.So the physical reason behind the observed behaviour of the capacitance is the presence of negative interfacial charges at the NPB/Alq interface under reverse bias.
With the presence of these interfacial charges one can now draw a schematic view of the potential and field distribution inside a hetero-layer device under different bias conditions as shown in Fig.28.For large negative bias the interfacial charge density is constant with the value of σ0 given above.Although the electric field is discontinuous at the interface (see Fig.28(a)),in the capacitance measurement one does not notice this because both organic layers are reverse biased and therefore have such a large resistance that one is always in the limit where the capacitance is the series sum of both layers.When the applied voltage approaches V0 the NPB layer reaches the flat-band condition (Fig.28(b)) and its resistance drops drastically leading to the increase of the measured capacitance to the value CAlq.For V0
英语翻译Thus the observation of two bias regimes with different overall capacitance can be explained by a drastic drop of the resistance of the NPB layer at the critical voltage V0.This means that at the voltage V0 (which is still below Vbi) the
这样的观察偏见政权,在两个不同的整体电容可以解释为一场激烈的阻力下降的临界电压层NPB证明.这意味着,在证明(的电压)仍然低于层NPB椎基底动脉供血不足的平带情况必须达到这样漏洞可以注入NPB从ITO阳极.然而,这反过来意味着应用的电压在Alq现在完全滴层.因此内部电场为零的层NPB−并且等于(证明)/ dAlq椎基底动脉供血不足的Alq层.证明从法律这样一个不连续的泊松比电场ΔF只能在一个接口界面电荷Q0引起的
如果这个效果是一种固有属性的接口,然后Alq NPB / Q0的大小不应该依靠外部参数,尤其是不上有机层的厚度.这反过来又意味着过渡电压证明应该表现出线性依赖于这Alq厚度,这其实看到图.25.从边坡ΔF =−0.35 MV /厘米级的一种直接得到了界面电荷密度作为σ0 = Q0 / qA =ΔF 0 /问=−−6.8厘米×1011 2.所以物质问题产生的原因之一是观察到的行为负电容的存在界面发生费用/ Alq NPB下反向偏倚.界面
存在量与这些界面的指控一个现在可以画一个图解的景色的潜力和场分布在一个hetero-layer装置在不同偏置条件,如图28日.对大型消极偏见界面电荷密度是恒定的价值σ0以上所填报.虽然电场是不连续界面(参见图28(a)),在电容测量一个人并不注意到这一点,因为它们都有机层可以偏正也因此具有很大的阻力,一个总在限制在电容之和是两层的系列.当电压的方法证明了层NPB触手可及