Charge transport in amorphous InGaZnO thin-film transistors
Charge transport in amorphous InGaZnO thin-film transistors
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DOI：
10.1103/physrevb.86.155319
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发表时间：
2012-10-26
影响因子：
3.7
通讯作者：
Kemerink, M.
中科院分区：
文献类型：
--
作者：
Germs, W. Chr.;Adriaans, W. H.;Kemerink, M.
研究了非晶金属氧化物半导体铟镓锌氧化物（a-IGZO）的电荷输运机制。我们测量了场效应迁移率和Seebeck系数（S = Δ V/Δ T）的a-IGZO在薄膜晶体管作为一个函数的电荷载流子密度为不同的温度。使用这些晶体管，我们进一步采用基于扫描开尔文探针的技术来确定用作建模基础的a-IGZO的态密度。在比较了两种常用的模型，带输运逾渗模型和迁移率边缘模型，我们发现，这两个模型不能描述的全部性质的电荷输运在a-IGZO半导体。因此，我们提出了一个模型，扩展的移动性边缘模型，允许可变范围跳跃低于移动性边缘。扩展的迁移率边缘模型给出了一个上级描述的实验结果。我们表明，电荷输运是由可变范围跳跃以下，而不是由带状运输以上的迁移率边缘。
We investigate the mechanism of charge transport in indium gallium zinc oxide (a-IGZO), an amorphous metal-oxide semiconductor. We measured the field-effect mobility and the Seebeck coefficient (S = Delta V/Delta T) of a-IGZO in thin-film transistors as a function of charge-carrier density for different temperatures. Using these transistors, we further employed a scanning Kelvin probe-based technique to determine the density of states of a-IGZO that is used as the basis for the modeling. After comparing two commonly used models, the band transport percolation model and a mobility edge model, we find that both cannot describe the full properties of the charge transport in the a-IGZO semiconductor. We, therefore, propose a model that extends the mobility edge model to allow for variable range hopping below the mobility edge. The extended mobility edge model gives a superior description of the experimental results. We show that the charge transport is dominated by variable range hopping below, rather than by bandlike transport above the mobility edge.