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Charge Transfer from Carbon Nanotubes to Silicon in Flexible Carbon Nanotube/Silicon Solar Cells |
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| Authors: | Xiaokai Li Marina Mariano Lyndsey McMillon‐Brown Jing‐Shun Huang Matthew Y Sfeir Mark A Reed Yeonwoong Jung André D Taylor |
| Affiliation: | 1. Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA;2. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, USA;3. Department of Electrical Engineering, Yale University, New Haven, CT, USA;4. Department of Applied Physics, Yale University, New Haven, CT, USA;5. NanoScience Technology Center, Electrical and Computer Engineering, Materials Science and Engineering, University of Central Florida, Orlando, FL, USA |
| Abstract: | Mechanical fragility and insufficient light absorption are two major challenges for thin flexible crystalline Si‐based solar cells. Flexible hybrid single‐walled carbon nanotube (SWNT)/Si solar cells are demonstrated by applying scalable room‐temperature processes for the fabrication of solar‐cell components (e.g., preparation of SWNT thin films and SWNT/Si p–n junctions). The flexible SWNT/Si solar cells present an intrinsic efficiency ≈7.5% without any additional light‐trapping structures. By using these solar cells as model systems, the charge transport mechanisms at the SWNT/Si interface are investigated using femtosecond transient absorption. Although primary photon absorption occurs in Si, transient absorption measurements show that SWNTs also generate and inject excited charge carriers to Si. Such effects can be tuned by controlling the thickness of the SWNTs. Findings from this study could open a new pathway for designing and improving the efficiency of photocarrier generation and absorption for high‐performance ultrathin hybrid SWNT/Si solar cells. |
| Keywords: | carbon nanotubes femtosecond transient absorption spectroscopy flexible photovoltaics hybrid solar cells silicon |