| AVS 62nd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Wednesday Sessions |
| Session 2D+EM+IS+MC+NS+SP+SS-WeA |
| Session: | Dopants and Defects in 2D Materials |
| Presenter: | Jiayu Wan, University of Maryland, College Park |
| Authors: | J. Wan, University of Maryland, College Park W. Bao, University of Maryland, College Park F. Gu, University of Maryland, College Park M. Fuhrer, Monash University, Malaysia L. Hu, University of Maryland, College Park |
| Correspondent: | Click to Email |
Transparent electrode materials are critical for optoelectronic devices such as touch screen and solar cells. Graphene has been widely studied as transparent electrodes for its unique physical properties. To further boost the performance of graphene based transparent electrodes, we novelized Li-ion intercalation in graphene, and achieved highest performance of carbon based transparent electrodes.[1] Transmission as high as 91.7% with a sheet resistance of 3.0 ohm/sq is achieved for 19-layer LiC6, which corresponds to a figure of merit (Sigmadc/Sigmaopt) at 1,400, significantly higher than any other continuous transparent electrodes. The unconventional modification of ultrathin graphite optoelectronic properties is explained by the suppression of interband optical transitions and a small intraband Drude conductivity near the interband edge. To achieve low cost, large scale graphene-based transparent electrodes, we further developed Na-ion intercalated printed reduced graphene oxide (RGO) film[2]. Unlike pristine graphene that inhibits Na-ion intercalation, the larger layer-layer distance of RGO allows Na-ion intercalation, leading to simultaneously much higher DC conductivity and higher optical transmittance. The typical increase of transmittance from 36% to 79% and decrease of sheet resistance from 83 kohms/sq to 311 ohms/sq in the printed network was observed after Na-ion intercalation. Compared with Li-intercalated graphene, Na-ion intercalated RGO shows much better environmental stability, which is likely due to the self-terminating oxidation of Na ions on the RGO edges. This study demonstrated the great potential of metal-ion intercalation to improve the performance of graphene-based materials for transparent conductor applications.
Reference
1. Jiayu Wana, Wenzhong Baoa, et al., Nature communications, 2014,5, 4224. (a equally contribution)
2. Jiayu Wan, Feng Gu, Wenzhong Bao, et al. Nano Letters, 2015, DOI: 10.1021/acs.nanolett.5b00300.