Cross-Linkable, Solvent-Resistant Fullerene Contacts for Robust and Efficient Perovskite Solar Cells with Increased JSCand VOC.
The active layers of perovskite solar cells are also structural layers and are central to ensuring that the structural integrity of the device is maintained over its operational lifetime. Our work evaluating the fracture energies of conventional and inverted solution-processed MAPbI3perovskite solar cells has revealed that the MAPbI3perovskite exhibits a fracture resistance of only ∼0.5 J/m2, while solar cells containing fullerene electron transport layers fracture at even lower values, below ∼0.25 J/m2. To address this weakness, a novel styrene-functionalized fullerene derivative, MPMIC60, has been developed as a replacement for the fragile PC61BM and C60transport layers. MPMIC60can be transformed into a solvent-resistant material through curing at 250 °C. As-deposited films of MPMIC60exhibit a marked 10-fold enhancement in fracture resistance over PC61BM and a 14-fold enhancement over C60. Conventional-geometry perovskite solar cells utilizing cured films of MPMIC60showed a significant, 205% improvement in fracture resistance while exhibiting only a 7% drop in PCE (13.8% vs 14.8% PCE) in comparison to the C60control, enabling larger VOCand JSCvalues. Inverted cells fabricated with MPMIC60exhibited a 438% improvement in fracture resistance with only a 6% reduction in PCE (12.3% vs 13.1%) in comparison to those utilizing PC61BM, again producing a higher JSC.
Department of Materials Science and Engineering, Stanford University , Stanford, California 94305-2205, United States.
Brian L
BL
Watson
Department of Applied Physics, Stanford University , Stanford, California 94305-2205, United States.
Nicholas
N
Rolston
Department of Materials Science and Engineering, Stanford University , Stanford, California 94305-2205, United States.
Kevin A
KA
Bush
Tomas
T
Leijtens
Department of Materials Science and Engineering, Stanford University , Stanford, California 94305-2205, United States.
Michael D
MD
McGehee
Department of Materials Science and Engineering, Stanford University , Stanford, California 94305-2205, United States.
Reinhold H
RH
Dauskardt
electron transport material; fracture; perovskite solar cells; reliability; solvent resistance