Injection barrier at metal/organic semiconductor junctions with a Gaussian density-of-states
Injection barrier at metal/organic semiconductor junctions with a Gaussian density-of-states
复制标题
具有高斯态密度的金属/有机半导体结处的注入势垒
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
G. Horowitz
中科院分区：
文献类型：
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作者：
Sungyeop Jung;Chang‐Hyun Kim;Y. Bonnassieux;G. Horowitz
我们使用高斯态密度 (GDOS) 对金属/有机半导体 (M/O) 结处的注入特性进行物理建模。通过分析和数值建模，可以计算有机整流二极管 (ORD) 中 M/O 结处的载流子浓度。结果表明，在应用肖特基-莫特规则时需要特别注意，该规则定义了理想金属/半导体结到 M/O 结的注入势垒 (IB)。通过系统地改变描述有机半导体中能量无序的 GDOS 的宽度，我们表明，最高占据分子轨道（HOMO）的边缘应定义为距 HOMO 最大值 σ2/2kBT ?> 高，而不是 2σ ?>，以保持肖特基-莫特规则的一致性。提出了 IB 的简单分析表达式，其中包含无序对促进电荷载流子注入的影响。还提出了 ORD 的模拟电流密度-电压特性来支持这些论点。
We physically model the injection characteristics at the metal/organic semiconductor (M/O) junctions with a Gaussian density-of-states (GDOS). By both analytical and numerical modelling, the charge carrier concentrations at the M/O junctions in an organic rectifying diode (ORD) are calculated. The results demonstrate a special attention required in the application of the Schottky–Mott rule, which defines the injection barrier (IB) for ideal metal/semiconductor junctions, to M/O junctions. By systematically changing the width of the GDOS that describes the energetic disorder in the organic semiconductor, we show that the edge of the highest-occupied molecular orbitals (HOMO) should be defined as σ2/2kBT ?> higher rather than 2σ ?> from the maximum of the HOMO to keep the consistency of the Schottky–Mott rule. A simple analytical expression for the IB is presented which contains the effect of the disorder in facilitating the charge carrier injection. Simulated current density-voltage characteristics of the ORDs are also presented to support the arguments.