Superior performance of V2O5 as hole selective contact over other transition metal oxides in silicon heterojunction solar cells
Transition metal oxides (TMOs) have recently been proved to efficiently serve as hole-selective contacts in crystalline silicon (c-Si) heterojunction solar cells. In the present work, two TMO/c-Si heterojunctions are explored using MoO3 (reference) and V2O5 as an alternative candidate. It has been f...
| Authors: | , , , , , |
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| Format: | article |
| Publication Date: | 2017 |
| Country: | España |
| Institution: | Universitat Politècnica de Catalunya (UPC) |
| Repository: | UPCommons. Portal del coneixement obert de la UPC |
| Language: | English |
| OAI Identifier: | oai:upcommons.upc.edu:2117/104004 |
| Online Access: | https://hdl.handle.net/2117/104004 https://dx.doi.org/10.1016/j.solmat.2017.04.042 |
| Access Level: | Open access |
| Keyword: | Solar cells Metallic oxides Metal oxide semiconductors Transition metal oxides Silicon solar cells Impedance spectroscopy Passivation Minority carrier lifetime Cèl·lules solars Òxids metàl·lics Metalls de transició Àrees temàtiques de la UPC::Energies::Energia solar fotovoltaica::Cèl·lules solars Àrees temàtiques de la UPC::Enginyeria electrònica::Microelectrònica |
| Summary: | Transition metal oxides (TMOs) have recently been proved to efficiently serve as hole-selective contacts in crystalline silicon (c-Si) heterojunction solar cells. In the present work, two TMO/c-Si heterojunctions are explored using MoO3 (reference) and V2O5 as an alternative candidate. It has been found that V2O5 devices present larger (16% improvement) power conversion efficiency mainly due to their higher open-circuit voltage. While V2O5/c-Si devices with textured front surfaces exhibit larger short-circuit currents, it is also observed that flat solar cell architectures allow for passivation of the V2O5/n-Si interface, giving significant carrier lifetimes of 200 µs (equivalent to a surface recombination velocity of Seff ~140 cm s-1) as derived from impedance analysis. As a consequence, a significant open-circuit voltage of 662 mV is achieved. It is found that, at the TMO/c-Si contact, a TMO work function enhancement ¿FTMO occurs during the heterojunction formation with the consequent dipole layer enlargement ¿’=¿+¿FTMO. Our results provide new insights into the TMO/c-Si contact energetics, carrier transport across the interface and surface recombination allowing for further understanding of the nature of TMO/c-Si heterojunctions. |
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