100% internal quantum efficiency in polychiral single-walled carbon nanotube bulk heterojunction/silicon solar cells

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• 作者：Francesco De Nicola^a ; ^b ; ^{francesco.denicola@iit.it} ; Matteo Salvato^b ; ^d ; Carla Cirillo^e ; ^d ; Michele Crivellari^f ; Maurizio Boscardin^f ; Maurizio Passacantando^g ; Michele Nardone^g ; Fabio De Matteis^h ; Nunzio Motta^c ; Maurizio De Crescenzi^b ; Paola Castrucci^b
• 关键词：Third generation solar cell ; Photovoltaic ; Bulk heterojunction ; Single-walled carbon nanotube ; Internal quantum efficiency ; Silicon ; Air-stable encapsulation ; Anti-reflective coating ; Hydrophobic film
• 刊名：Carbon
• 出版年：2017
• 出版时间：April 2017
• 年：2017
• 卷：114
• 期：Complete
• 页码：402-410
• 全文大小：1737 K
• 卷排序：114

文摘

Bulk heterojunction films made of polychiral single-walled carbon nanotubes (SWCNTs) form efficient heterojunction solar cells with n-type crystalline silicon (n-Si), due to their superior electronic, optical, and electrical properties. The films are multi-functional, since their hierarchical surface morphology provides a biomimetical anti-reflective, air-stable, and hydrophobic encapsulation for Si. Also, the films have a large effective area conferring them high optical absorption, which actively contribute to the solar energy harvesting together with Si. Here, we report photovoltaic devices with photoconversion efficiency up to 12% and a record 100% internal quantum efficiency (IQE). Such unprecedented IQE value is truly remarkable and indicates that every absorbed photon from the device, at some wavelengths, generates a pair of separated charge carriers, which are collected at the electrodes. The SWCNT/Si devices favor high and broadband carrier photogeneration; charge dissociation of ultra-fast hot excitons; transport of electrons through n-Si and high-mobility holes through the SWCNT percolative network. Moreover, by varying the film thickness, it is possible to tailor the physical properties of such a two-dimensional interacting system, therefore the overall device features. These results not only pave the way for low-cost, high-efficient, and broadband photovoltaics, but also are promising for the development of generic SWCNT-based optoelectronic applications.