Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK.
Nanoscale Res Lett. 2009 Mar 19;4(7):635-9. doi: 10.1007/s11671-009-9287-9.
Charge exchange at the bulk heterojunctions of composites made by mixing single wall nanotubes (SWNTs) and polymers show potential for use in optoelectronic devices such as solar cells and optical sensors. The density/total area of these heterojunctions is expected to increase with increasing SWNT concentration but the efficiency of solar cell peaks at low SWNT concentrations. Most researchers use current-voltage measurements to determine the evolution of the SWNT percolation network and optical absorption measurements to monitor the spectral response of the composites. However, these methods do not provide a detailed account of carrier transport at the concentrations of interest; i.e., near or below the percolation threshold. In this article, we show that capacitance-voltage (C-V) response of (metal)-(oxide)-(semiconducting composite) devices can be used to fill this gap in studying bulk heterojunctions. In an approach where we combine optical absorption methods withC-Vmeasurements we can acquire a unified optoelectronic response from P3HT-SWNT composites. This methodology can become an important tool for optoelectronic device optimization.
在由单壁碳纳米管（SWNTs）和聚合物混合制成的复合材料的体异质结处进行电荷交换，有望用于光电设备，如太阳能电池和光学传感器。这些异质结的密度/总面积预计会随着 SWNT 浓度的增加而增加，但太阳能电池的效率在低 SWNT 浓度下达到峰值。大多数研究人员使用电流-电压测量来确定 SWNT 渗流网络的演变，并使用光学吸收测量来监测复合材料的光谱响应。然而，这些方法并不能详细说明在感兴趣的浓度下（即在渗流阈值附近或以下）的载流子输运情况。在本文中，我们表明，（金属）-（氧化物）-（半导体复合材料）器件的电容-电压（C-V）响应可用于填补研究体异质结的这一空白。在我们将光学吸收方法与 C-V 测量相结合的方法中，我们可以从 P3HT-SWNT 复合材料中获得统一的光电响应。这种方法可以成为光电设备优化的重要工具。
