Strong Light-Matter Interactions at Graphene-Heterostructures for Photonics and Photo-To-Energy Conversions
Chun-Wei Chen1*
1Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan
* presenting author:Chun-Wei Chen,
In this talk, I would like to present the strong light-matter interactions at graphene/heterostructure for photonics and photovoltaics. I would like to introduce precisely controlled ultrastrong photoinduced modulation doping based on graphene/TiOx heterostructure, where trap-state-mediated photoinduced charge transfer from the remote bulk TiOx ultrathin film to graphene resulted in a strikingly high n-type doping level (>1013 cm-2), showing both unique advantages of using the conventional chemical doping (high doping concentrations) and photoinduced doping (reversible and controllable).[1] A novel approach to precisely control the band gap opening of a bilayer graphene/TiOx heterostructure by optical modulation will be addressed. In addition, I would like to demonstrate interesting optically controllable graphene electronics due to strong light-matter interactions at graphene heterostructure. For example, the dual carrier-typed transport behavior of a graphene transistor by wavelength-selective illumination will be demonstrated [2]. A new concept of photoactive graphene/TiOx heterostructure transparent electrode for photovoltaic application will be also shown [3]. The precisely controllable photoindcued charge transfer can be also applied to a black phosphorus FET to achieve a tunable carrier transport by light illumination. [4] Finally, I would like to present our recent discovery of crack-filled graphene (CFG) films and its application to photo-to-energy conversion [5,6]

[1]. Advanced Materials, Vol.27, 7809, (2015)
[2]. Advanced Materials, Vol.27, 282, (2015)
[3]. Energy & Environmental Science, 8, 2085, (2015)
[4]. ACS Photonics, Vol.3, 1102, (2016)
[5]. Advanced Materials Vol.25, 4521, (2013)
[6]. Advanced Materials Vol.27, 1724, (2015)

Keywords: graphene, 2D materials, photonics, energy conversion