Undoped tin dioxide transparent electrodes for efficient and cost-effective indoor organic photovoltaics (SnO2electrode for indoor organic photovoltaics)

• Published in: NPG Asia materials 2021, Vol.13 (1), Article 43
• Main Authors: Lee, Jung-Hoon, You, Young-Jun, Saeed, Muhammad Ahsan, Kim, Sang Hyeon, Choi, Su-Hwan, Kim, Sungmin, Lee, Sae Youn, Park, Jin-Seong, Shim, Jae Won
• Format: Article
• Language: English
• Subjects: 132/122; 639/166/987; 639/766/1130; Atomic layer epitaxy; Biomaterials; Chemistry and Materials Science; Dioxides; Electrical resistivity; Electronic devices; Energy conversion efficiency; Energy Systems; Illumination; Indene; Indium tin oxides; Light emitting diodes; Light sources; Low temperature; Luminance; Materials Science; Optical and Electronic Materials; Photovoltaic cells; Structural Materials; Surface and Interface Science; System effectiveness; Thin Films; Tin; Tin dioxide
• ISSN: 1884-4049; 1884-4057
• DOI: 10.1038/s41427-021-00310-2

Indoor organic photovoltaics (OPVs) are currently being investigated for small-scale energy generation from artificial light sources to power small electronic devices. Despite recent progress in increasing the power conversion efficiency (PCE) of indoor OPVs, the widespread use of expensive indium tin oxide (ITO) as a transparent conducting electrode (TCE) leads to long energy payback times. This study provides a novel and comprehensive description of low-temperature atomic layer deposition (ALD)-processed indium-free tin dioxide (SnO 2 ) films as inexpensive and efficient TCEs for indoor OPVs. These highly conformal and defect-free ALD-fabricated SnO 2 films are applied to a poly(3-hexylthiophene):indene-C 60 bisadduct-based OPV system. Under 1 sun illumination, an OPV with an SnO 2 TCE exhibits limited operational capacity because of the high sheet resistance (~98 Ω sq −1 ) of the SnO 2 layers. However, under a light-emitting diode (LED) lamp with a luminance of 1000 lx, the series resistance, which is related to the sheet resistance, has a marginal effect on the performance of the indoor OPV system, showing a PCE of 14.6 ± 0.3%. A reference OPV with an ITO TCE has a slightly lower PCE of 13.3 ± 0.8% under the same LED conditions. These results suggest that SnO 2 TCEs can be efficient and cost-effective replacements for ITO TCEs in indoor OPV systems. Indium-free un-doped tin dioxide (SnO 2 ) serves as a transparent conducting electrode for indoor organic photovoltaics (OPVs). SnO 2 OPV systems demonstrate superior indoor performance compared with indium tin oxide (ITO)-based systems. SnO 2 -based OPV systems shows 14.6% efficiency under 1000 lx of LED illumination. Low-cost SnO 2 can be a promising substitute for expensive ITOs in indoor OPV systems.