[4] Fang, Y.; Bi, C.; Wang, D.; Huang, J., ACS Energy Letters, (2017) 2, 782. ... T.; Betancourt-Solis, G.; Rodriguez, G.; Echegoyen, L., ACS Applied Materials ...
NEW FULLERENE DERIVATIVES AS ELECTRON TRANSPORTING MATERIALS IN PEROVSKITE SOLAR CELLS Olivia Fernandez-Delgado1, Edison Castro1, Funda Arslan2 and Luis Echegoyen1* 1Department
of Chemistry, University of Texas at El Paso, El Paso, Texas, 79902 2 Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nurnberg. Abstract: In less than a decade Perovskite Solar Cells (PSCs) have experienced an incredible rise in power conversion efficiencies (PCE) starting from 3.8% in 2009 to 22.1% in 2016.[1, 2] Due to their electron transporting properties and low cost deposition techniques, fullerene derivatives are the most attractive semiconductors used as electron transporting materials (ETMs) in PSCs. Devices based on these compounds have achieved a maximum PCE of 20.15%, [3] reduced hysteresis, and improved stability.[4-6] Here we report the synthesis, characterization and the use of four new C60 and C70 derivatives as ETMs in Inverted PSCs.
Introduction
Device characterization
In the past few years the development of organic-inorganic hybrid perovskites solar cells has been taken into more consideration because of the increment in their PCE from 3.8% to 22.1%. [3] These materials are promising in the fabrication of new devices with enhanced properties for commercial applications in the photovoltaic technology. To find more viable and efficient configurations, the inverted planar PSCs have been the ones with more promising results due to their easy fabrication, high efficiencies and the many possibilities of changing not only the Hole Transporting Materials (HTMs) but the ETMs. In this configuration fullerenes have been especially effective, with PC61BM being the most used fullerene derivative.
1
2
3
Results
4
Figure 3: Energy levels diagram
Figure 2: Inverted PSC architecture for planar solar cells
2
1 77.38°
Synthesis
1
90.07°
3 79.09°
Figure 4: J-V curves for inverted perovskite solar cells
2
86.63°
4
3
88.61°
4
80.72°
Figure 5: Contact angle measurements
Comp.
Jsc (mA/cm2)
Voc (V)
FF
PCE (%)
PC61BM
21.1
0.88
0.80
14.9
PC71BM
21.1
0.89
0.81
15.2
1
22.1
0.88
0.84
16.3
2
22.3
0.91
0.83
16.8
3
21.9
0.89
0.81
15.7
4
22.0
0.88
0.83
16.1
Conclusions Four new fullerene derivatives were synthesized and completely characterized by 1H NMR, 13C NMR, and MALDITOF (not shown). All of the new derivatives performed better than PC61BM and PC71BM, used as controls. From this group of new fullerenes the one that performed best was compound 2.
Acknowledgements
Fullerene Perovskite PEDOT:PSS ITO Scheme 1: Synthesis of the new fullerene derivatives Glass
NSF Grant DMR-1205302 (PREM Program) Figure 6: Scanning electron microscopy (SEM) characterization
1
1
PC61BM PC61BM
1
2
PC71BM
C60 1
1
Figure 1: 1H and 13C NMR Characterization of the compound 1
PC71BM
Figure 7: Electron mobility measurements
3
4
References [1] Contributors, W. C., File:Best Research-Cell Efficiencies, In Wikimedia Commons, the free media repository.: (2017). [2] Correa-Baena, J.-P.; Abate, A.; Saliba, M.; Tress, W.; Jesper Jacobsson, T.; Gratzel, M.; Hagfeldt, A., Energy & Environmental Science, (2017) 10, 710. [3] Luo, D.; Zhao, L.; Wu, J.; Hu, Q.; Zhang, Y.; Xu, Z.; Liu, Y.; Liu, T.; Chen, K.; Yang, W.; Zhang, W.; Zhu, R.; Gong, Q., Advanced Materials, (2017) 29, 1604758. [4] Fang, Y.; Bi, C.; Wang, D.; Huang, J., ACS Energy Letters, (2017) 2, 782. [5] Tian, C.; Kochiss, K.; Castro, E.; Betancourt-Solis, G.; Han, H.; Echegoyen, L., Journal of Materials Chemistry A, (2017) 5, 7326. [6] Tian, C.; Castro, E.; Wang, T.; Betancourt-Solis, G.; Rodriguez, G.; Echegoyen, L., ACS Applied Materials & Interfaces, (2016) 8, 31426.
