Characterization of transition metal Oxide/Silicon heterojunctions for solar cell applications
During the last decade, transition metal oxides have been actively investigated as hole- and electron-selective materials in organic electronics due to their low-cost processing. In this study, four transition metal oxides (V2O5, MoO3, WO3, and ReO3) with high work functions (>5 eV) were thermall...
| Authors: | , , , , |
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| Format: | article |
| Publication Date: | 2015 |
| 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:2117/87667 |
| Online Access: | https://hdl.handle.net/2117/87667 https://dx.doi.org/10.3390/app5040695 |
| Access Level: | Open access |
| Keyword: | Solar cells Transition metal compounds Transition metal oxides Silicon heterojunction solar cells Vanadium oxide Molybdenum oxide Tungsten oxide Rhenium oxide Cèl·lules solars Metalls de transició -- Compostos Àrees temàtiques de la UPC::Energies::Energia solar fotovoltaica::Cèl·lules solars |
| Summary: | During the last decade, transition metal oxides have been actively investigated as hole- and electron-selective materials in organic electronics due to their low-cost processing. In this study, four transition metal oxides (V2O5, MoO3, WO3, and ReO3) with high work functions (>5 eV) were thermally evaporated as front p-type contacts in planar n-type crystalline silicon heterojunction solar cells. The concentration of oxygen vacancies in MoO3-x was found to be dependent on film thickness and redox conditions, as determined by X-ray Photoelectron Spectroscopy. Transfer length method measurements of oxide films deposited on glass yielded high sheet resistances (~109 O/sq), although lower values (~104 O/sq) were measured for oxides deposited on silicon, indicating the presence of an inversion (hole rich) layer. Of the four oxide/silicon solar cells, ReO3 was found to be unstable upon air exposure, while V2O5 achieved the highest open-circuit voltage (593 mV) and conversion efficiency (12.7%), followed by MoO3 (581 mV, 12.6%) and WO3 (570 mV, 11.8%). A short-circuit current gain of ~0.5 mA/cm2 was obtained when compared to a reference amorphous silicon contact, as expected from a wider energy bandgap. Overall, these results support the viability of a simplified solar cell design, processed at low temperature and without dopants. |
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