Influence of surface electrode on luminescent properties of nanocrystalline silicon electroluminescent device.
Influence of surface electrode on luminescent properties of nanocrystalline silicon electroluminescent device.
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DOI：
10.1166/jnn.2007.130
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发表时间：
2007-02
影响因子：
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通讯作者：
Keisuke Sato;K. Hirakuri
中科院分区：
文献类型：
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作者：
Keisuke Sato;K. Hirakuri
研究了以氧化铟锡（ITO）和金（Au）薄膜为表面电极的纳米晶硅（nc-Si）基红色电致发光（EL）器件的电学和发光特性，以及两个电极的透射率和电阻率随不同薄膜厚度的变化。ITO电极的膜厚度从50 nm增加到200 nm导致电阻率从2.0 × 10（-3）Ω cm降低到9.1 × 10（-4）Ω cm，并且在红色区域中的透射率几乎相同（83-92%）。另一方面，随着膜厚度从10 nm增加到80 nm，Au电极的电阻率从1.8 × 10（-4）Ω cm降低到1.6 × 10（-5）Ω cm，红色区域的透射率从42%降低到1.8%。此外，通过分别施加高于4.5和2.5 V的直流正向电压和/或通过分别流过高于53和38 mA/cm 2的正向电流密度，获得了来自使用厚度分别为200和10 nm的ITO和/或Au电极的EL器件的红色发光。然而，与具有Au电极的EL器件的发光强度相比，具有ITO电极的EL器件的发光强度增强超过约一个数量级。这是由于ITO电极的红色区域中的高透射率值。我们认为ITO电极是实现高亮度nc-Si基电致发光器件的最佳表面电极。
We describe the electrical and luminescence properties of nanocrystalline silicon (nc-Si) based red electroluminescent (EL) devices using an indium tin oxide (ITO) and/or gold (Au) films as a surface electrode, and the variation in the transmittance and resistivity of two electrodes with various film thicknesses. The increase in the film thickness from 50 to 200 nm of the ITO electrode led to the lowering of resistivity from 2.0 x 10(-3) to 9.1 x 10(-4) omega cm and almost the same value (83-92%) of transmittance in the red region. On the other hand, the Au electrode was lowered the resistivity from 1.8 x 10(-4) to 1.6 x 10(-5) omega cm and the transmittance in the red region from 42 to 1.8% with increasing the film thickness from 10 to 80 nm. Moreover, the red luminescence from the EL devices using the ITO and/or Au electrodes having thickness of 200 and 10 nm, respectively, obtained by applying the direct current forward voltage above 4.5 and 2.5 V and/or by flowing the forward current density above 53 and 38 mA/cm2, respectively. However, the luminescence intensity of EL device with the ITO electrode strengthened more than about one order of magnitude in comparison to that of the EL device with the Au electrode. This was due to the high value of transmittance in the red region of the ITO electrode. We suggest that the ITO electrode is an optimum surface electrode for the realization of nc-Si based EL device with the high brightness.