Details
| Original language | English |
|---|---|
| Pages (from-to) | 110-116 |
| Number of pages | 7 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 131 |
| Publication status | Published - Dec 2014 |
Abstract
We measure saturation current densities down to J0=80 fA/cm2 for organic-silicon heterojunctions with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as an organic layer. This remarkably low J0 value corresponds to implied open-circuit voltages around 690 mV, demonstrating the high-efficiency potential of this novel junction type. However, experimentally realized organic-silicon heterojunction solar cells showed relatively moderate efficiencies so far, typically below 12%. We demonstrate in this study that these solar cells were limited by the fact that the organic-silicon junction was localized on the cell front, resulting in a significant parasitic light absorption within the PEDOT:PSS layer. In addition, the rear surface of these front-junction solar cells was either poorly passivated or not passivated at all. In this paper, we overcome these limitations by proposing a back-junction organic-silicon solar cell, the so-called "BackPEDOT" cell. We show that placing PEDOT:PSS on the rear side instead of the front surface avoids parasitic light absorption within the PEDOT:PSS and allows for an improved surface passivation. We fabricate and characterize BackPEDOT solar cells and achieve very high open-circuit voltages of up to 663 mV and short-circuit current densities of up to 39.7 mA/cm2. Despite the relatively high series resistances of our first BackPEDOT cells, we achieve an energy conversion efficiency of 17.4%. The measured pseudo efficiency of the best cell of 21.2% suggests that our novel BackPEDOT cell concept is indeed suitable for easy-to-fabricate high-efficiency solar cells after some further optimization to reduce the contact resistance between the PEDOT and the n-type silicon wafer. Based on realistic assumptions we conclude that Back PEDOT cells have an efficiency potential exceeding 22%.
Keywords
- Heterojunction/Organic-silicon, PEDOT:PSS, Saturation current density, Solar cell
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Surfaces, Coatings and Films
Sustainable Development Goals
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Solar Energy Materials and Solar Cells, Vol. 131, 12.2014, p. 110-116.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Organic-silicon heterojunction solar cells on n-type silicon wafers
T2 - The BackPEDOT concept
AU - Zielke, Dimitri
AU - Pazidis, Alexandra
AU - Werner, Florian
AU - Schmidt, Jan
N1 - Publisher Copyright: © 2014 Elsevier B.V.
PY - 2014/12
Y1 - 2014/12
N2 - We measure saturation current densities down to J0=80 fA/cm2 for organic-silicon heterojunctions with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as an organic layer. This remarkably low J0 value corresponds to implied open-circuit voltages around 690 mV, demonstrating the high-efficiency potential of this novel junction type. However, experimentally realized organic-silicon heterojunction solar cells showed relatively moderate efficiencies so far, typically below 12%. We demonstrate in this study that these solar cells were limited by the fact that the organic-silicon junction was localized on the cell front, resulting in a significant parasitic light absorption within the PEDOT:PSS layer. In addition, the rear surface of these front-junction solar cells was either poorly passivated or not passivated at all. In this paper, we overcome these limitations by proposing a back-junction organic-silicon solar cell, the so-called "BackPEDOT" cell. We show that placing PEDOT:PSS on the rear side instead of the front surface avoids parasitic light absorption within the PEDOT:PSS and allows for an improved surface passivation. We fabricate and characterize BackPEDOT solar cells and achieve very high open-circuit voltages of up to 663 mV and short-circuit current densities of up to 39.7 mA/cm2. Despite the relatively high series resistances of our first BackPEDOT cells, we achieve an energy conversion efficiency of 17.4%. The measured pseudo efficiency of the best cell of 21.2% suggests that our novel BackPEDOT cell concept is indeed suitable for easy-to-fabricate high-efficiency solar cells after some further optimization to reduce the contact resistance between the PEDOT and the n-type silicon wafer. Based on realistic assumptions we conclude that Back PEDOT cells have an efficiency potential exceeding 22%.
AB - We measure saturation current densities down to J0=80 fA/cm2 for organic-silicon heterojunctions with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as an organic layer. This remarkably low J0 value corresponds to implied open-circuit voltages around 690 mV, demonstrating the high-efficiency potential of this novel junction type. However, experimentally realized organic-silicon heterojunction solar cells showed relatively moderate efficiencies so far, typically below 12%. We demonstrate in this study that these solar cells were limited by the fact that the organic-silicon junction was localized on the cell front, resulting in a significant parasitic light absorption within the PEDOT:PSS layer. In addition, the rear surface of these front-junction solar cells was either poorly passivated or not passivated at all. In this paper, we overcome these limitations by proposing a back-junction organic-silicon solar cell, the so-called "BackPEDOT" cell. We show that placing PEDOT:PSS on the rear side instead of the front surface avoids parasitic light absorption within the PEDOT:PSS and allows for an improved surface passivation. We fabricate and characterize BackPEDOT solar cells and achieve very high open-circuit voltages of up to 663 mV and short-circuit current densities of up to 39.7 mA/cm2. Despite the relatively high series resistances of our first BackPEDOT cells, we achieve an energy conversion efficiency of 17.4%. The measured pseudo efficiency of the best cell of 21.2% suggests that our novel BackPEDOT cell concept is indeed suitable for easy-to-fabricate high-efficiency solar cells after some further optimization to reduce the contact resistance between the PEDOT and the n-type silicon wafer. Based on realistic assumptions we conclude that Back PEDOT cells have an efficiency potential exceeding 22%.
KW - Heterojunction/Organic-silicon
KW - PEDOT:PSS
KW - Saturation current density
KW - Solar cell
UR - http://www.scopus.com/inward/record.url?scp=84908412381&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2014.05.022
DO - 10.1016/j.solmat.2014.05.022
M3 - Article
AN - SCOPUS:84908412381
VL - 131
SP - 110
EP - 116
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
SN - 0927-0248
ER -