Materials Production

Camilla Coletti

Crystal synthesis - Camilla Coletti

The scalable synthesis of highly crystalline graphene, other 2D materials and van der Waals heterostacks is of fundamental importance to develop a 2D-material based technology especially in the fields of electronics and optoelectronics.

Our research targets span from fundamental ones to strictly applicative ones. We are actively addressing the following objectives:

  1. wafer scale integration of graphene
  2. synthesis of vertical 2D heterostacks for optoelectronics and spintronics
  3. study of fundamental properties of novel 2D transition metal dichalcogenides (TMDs)

In our laboratories we adopt a chemical vapor deposition (CVD) approach to synthesize 2D materials with exceptional electronic, optical and tribological properties. The synthetized materials are thouroughly investigated with advanced microscopic and spectroscopic techniques as well as via transport measurements. The structural and electronic properties of 2D materials and their heterostacks are tailored via atomic intercalation and the realization of superlattices. A strong collaboration is carried on with research groups involved in Graphene Flagship, in particular Spintronics (WP2), Photonics and Optoelectronics (WP8) and Wafer-scale System Integration (WP10).

Thanks to this activities, we have developed a rapid and industrially appealing CVD process for the synthesis of millimeter sized single-crystal graphene with remarkable transport properties Miseikis e at, 2D Mater 2 2015. Furthermore we have recently presented a novel approach for the seeded growth of high-quality large single-crystal graphene (Fig.2) Miseikis et al, 2D Mater 4 2017. This deterministic growth approach is especially promising for wafer-scale integration of graphene. Also, we have realized via CVD 2D vertical heterostacks with atomically sharp interfaces such as graphene/hBN Mishra et al, Carbon 96 2016, TMD/graphene and TMD/hBN. The latter displays exceptional optical properties such as a robust polarization conservation at room temperature Rossi et al, 2D Mater 3 2016.

Connection with Graphene Flagship project

WP3 Enabling Materials

  • Task 3.1.3 Growth of transition metal dichalcogenides and black phosphorous with various and complementary techniques;
  • Task 3.1.4 Growth and characterization of single layer boron nitride (BN) and G/BN heterostructures;
  • Task 3.1.7 Growth and characterization of multilayered heterostructures G/2D, 2D/2D

Fig. 1. (a)–(d) Proposed process flow for deterministic growth of single-crystal graphene. (e) SEM image of an array of graphene single-crystals. (f) Optical image of a graphene array on oxidised Cu foil. (g) Optical image of single-crystal array transferred onSi/SiO2 substrate with alignment markers. In figures (e)–(g) the array periodicity is 200 μm and crystal size is ~100 μm Miseikis et al, 2D Mater 4 2017