High-work-function metal/carbon nanotube/low-work-function metal hybrid junction photovoltaic device

Changxin Chen, Tiening Jin, Liangming Wei, Yong Li, Xiaodong Liu, Ying Wang, Liying Zhang, Chenghao Liao, Nantao Hu, Chuanjuan Song, Yafei Zhang
2015 NPG Asia Materials  
Photovoltaic devices based on nanotechnology have attracted much attention because of their great potential for application in electronic and energy fields. Here, a photovoltaic device based on a high-work-function metal/single-walled carbon nanotube (SWNT)/low-work-function metal hybrid junction was investigated. In the device, asymmetric metal electrodes (palladium and aluminum) were fabricated on opposite ends of a single semiconducting SWNT, which was used as the photosensitive material.
more » ... s structure allowed a strong built-in electric field to be generated in the SWNT to efficiently separate photogenerated electron-hole pairs and achieve good photovoltaic effect. In the dark, the device behaved as a gate-dependent Schottky diode and exhibited the electrical characteristics of a rectifier. The SWNT diameter (band gap) was found to have a significant effect on the device characteristics. For the device fabricated with a 1.4-nm-diameter SWNT, a high rectification ratio (I forward /I reverse ) of 410 3 could be achieved in the dark. Under monochromatic illumination, this device had an open-circuit voltage of 0.15 V and a high quantum efficiency of~75%.
doi:10.1038/am.2015.112 fatcat:edrgcw6tdzfhhmqwfbzig4kgue