High open-circuit voltage in transition metal dichalcogenide solar cells
| Autor: | Ignacio Tobías, Elisa Antolin, Pablo Garcia-Linares, Takashi Taniguchi, Carlos Macias, James Kerfoot, Simon A. Svatek, Carlos Bueno-Blanco, Kenji Watanabe, Marius H. Zehender, Peter H. Beton, Der-Yuh Lin |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
FOS: Physical sciences 02 engineering and technology Applied Physics (physics.app-ph) Electroluminescence 010402 general chemistry 7. Clean energy 01 natural sciences General Materials Science Electrical and Electronic Engineering Homojunction Ohmic contact Quantum tunnelling Renewable Energy Sustainability and the Environment business.industry Open-circuit voltage Doping Energy conversion efficiency Heterojunction Physics - Applied Physics 021001 nanoscience & nanotechnology 0104 chemical sciences Energías Renovables Optoelectronics 0210 nano-technology business |
| Zdroj: | Nano Energy, ISSN 2211-2855, 2020 Archivo Digital UPM Universidad Politécnica de Madrid |
| Popis: | The conversion efficiency of ultra-thin solar cells based on layered materials has been limited by their open-circuit voltage, which is typically pinned to a value under 0.6 V. Here we report an open-circuit voltage of 1.02 V in a 120 nm-thick vertically stacked homojunction fabricated with substitutionally doped MoS2. This high open-circuit voltage is consistent with the band alignment in the MoS2 homojunction, which is more favourable than in widely-used TMDC heterostructures. It is also attributed to the high performance of the substitutionally doped MoS2, in particular the p-type material doped with Nb, which is demonstrated by the observation of electroluminescence from tunnelling graphene/BN/MoS2 structures in spite of the indirect nature of bulk MoS2. We find that illuminating the TMDC/metal contacts decreases the measured open-circuit voltage in MoS2 van der Waals homojunctions because they are photoactive, which points to the need of developing low-resistance, ohmic contacts to doped MoS2 in order to achieve high efficiency in practical devices. The high open-circuit voltage demonstrated here confirms the potential of layered transition-metal dichalcogenides for the development of highly efficient, ultra-thin solar cells. |
| Databáze: | OpenAIRE |
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