High‐Efficiency Nonfullerene Organic Solar Cells with a Parallel Tandem Configuration
Abstract
In this work, a highly efficient parallel connected tandem solar cell utilizing a nonfullerene acceptor is demonstrated. Guided by optical simulation, each of the active layer thicknesses of subcells are tuned to maximize its light trapping without spending intense effort to match photocurrent. Interestingly, a strong optical microcavity with dual oscillation centers is formed in a back subcell, which further enhances light absorption. The parallel tandem device shows an improved photon‐to‐electron response over the range between 450 and 800 nm, and a high short‐circuit current density (J SC) of 17.92 mA cm−2. In addition, the subcells show high fill factors due to reduced recombination loss under diluted light intensity. These merits enable an overall power conversion efficiency (PCE) of >10% for this tandem cell, which represents a ≈15% enhancement compared to the optimal single‐junction device. Further application of the designed parallel tandem configuration to more efficient single‐junction cells enable a PCE of >11%, which is the highest efficiency among all parallel connected organic solar cells (OSCs). This work stresses the importance of employing a parallel tandem configuration for achieving efficient light harvesting in nonfullerene‐based OSCs. It provides a useful strategy for exploring the ultimate performance of organic solar cells.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 10, 2017
- Source ID
- 10.1002/adma.201702547
Entities
People
- Alex K.‐y. Jen
- Francis Lin
- Jiangsheng Yu
- Lijian Zuo
- Weihua Tang
- Xueliang Shi
Organizations
- City University of Hong Kong
- Nanjing University of Science and Technology
- Office of Naval Research
- University of Washington