| AVS 66th International Symposium & Exhibition | |
| 2D Materials | Wednesday Sessions |
| Session 2D+EM+MN+NS-WeA |
| Session: | 2D Device Physics and Applications |
| Presenter: | Avra Bandyopadhyay, University of North Texas |
| Authors: | R.F. Hossain, University of North Texas A.B. Kaul, University of North Texas A.S. Bandyopadhyay, University of North Texas |
| Correspondent: | Click to Email |
Tungsten di-selenide (WSe2), a classic representative of two dimensional (2D) layered materials has recently drawn much attention due to its unique optoelectronic properties, offering a potential platform to construct hetero-structure photodetector (PD) for ultrafast optoelectronic devices on low-cost, flexible substrates [1,2]. As WSe2 exhibits a weak van der Waals interlayer bonding, one of the approaches to obtain 2D WSe2 is through top-down liquid phase exfoliation (LPE), where the bulk crystal is dispersed in a solvent through appropriate sonication and centrifugation conditions [1]. In this work, we report on the synthesis of WSe2 via LPE and the first-ever assembly of an all inkjet printed WSe2-graphene hetero-structure PD on flexible polyimide film, where the WSe2 acted as a photo-active semiconductor and graphene was the carrier collector. The inkjet printed PD was photo-responsive to broadband incoming radiation in the visible regime, and exhibited a high photoresponsivity R ~ 0.70 A/W, and detectivity D ~ 3 × 1010 Jones. The strain-dependent measurements were conducted with bending for different curvatures, indicating the feasibility of such devices for large format arrays printed on flexible substrates. The capacitance-frequency (C-f) measurements were performed to investigate the trap states. In conclusion, this unique all inkjet printed 2D hetero-junction photodetector formed on flexible and conformable substrate was successfully shown to be highly photo-responsive to a wide range of light intensities and strain levels, making it a promising prospect for scalable flexible electronic and optoelectronic devices and circuitry.
References:
[1] Kelly, A. G., Hallam, T., Backes, C., Harvey, A., Esmaeily, A. S., Godwin, I., ... & Kinge, S. (2017). All-printed thin-film transistors from networks of liquid-exfoliated nanosheets. Science, 356(6333), 69-73.
[2] Pradhan, N. R., Ludwig, J., Lu, Z., Rhodes, D., Bishop, M. M., Thirunavukkuarasu, K., ... & Balicas, L. (2015). High photoresponsivity and short photoresponse times in few-layered WSe2 transistors. ACS applied materials & interfaces, 7(22), 12080-12088.