Abstract
Efficient charge collection is critical in large area (quasi-) planar configuration perovskite solar cells (PSCs) as the cell operation relies on the diffusion of photo-generated charge carriers to charge collector layers. Many defects/traps in the polycrystalline perovskite absorber layer strongly affect the charge collection efficiency because the 2D-like top charge collection layer barely penetrates into the 3D grain boundaries in the perovskite layer to efficiently collect the charge carrier. Inspired by blood capillaries for efficient mass exchange, a charge-collection nano-network for efficient charge collection was incorporated into the perovskite absorber using low-cost, stable amino-functionalized graphene (G-NH2). The integration of such an unprecedented structure enables very efficient charge collection, leading to the significant enhancement of the power conversion efficiency of 1 × 1 cm2 MAPbI3 PSCs from 14.4 to 18.7% with higher reproducibility, smaller hysteresis and enhanced stability. The physicochemical mechanisms underlying the role of this nano charge-collection nano-network in boosting the charge collection in PSCs are elucidated comprehensively, using a combined experimental and theoretical approach, pointing to a new direction towards up-scaling of high-efficiency PSCs.
Original language | English (US) |
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Pages (from-to) | 868-873 |
Number of pages | 6 |
Journal | Materials Horizons |
Volume | 5 |
Issue number | 5 |
DOIs | |
State | Published - Sep 2018 |
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Process Chemistry and Technology
- Electrical and Electronic Engineering