Optical properties of spray coated layers with carbon nanotubes and graphene nanoplatelets Zofia Lorenc a , Jakub Krzeminski b , Grzegorz Wroblewski b , and Leszek Salbut a a Institute of Micromechanics and Photonics b Institute of Metrology and Biomedical Engineering, Faculty of Mechatronics, Warsaw Univ. of Technology, Andrzeja Boboli 8 St., 02-525 Warsaw, Poland ABSTRACT Carbon nanotubes and graphene are allotropic forms of carbon. Graphene is a two dimensional (2D) form of atomic-scale, hexagonal lattice, while carbon nanotube is a cylindrical nanostructure composed of a rolled sheet of graphene lattice at specific and discrete angles. Both of discussed materials reveal a high potential for modern engineering, especially in organic and printed electronics. High transparency in the visible part of the electromagnetic spectrum and low electrical resistance are desirable features in various applications and may be fulfilled with studied carbon nanomaterials. They have chances to become an important technological improvement in customers electronic devices by applying them to production of electrodes in flexible screens and light sources. Graphene and carbon nanotubes are conceptually similar. However, characteristic properties of these two substances are different. In the article authors present the transmission characteristics in visible electromagnetic spectrum for samples made with different nanofiller inks. Particularly in wearable electronics the balance between transparency and resistance of carbon electrodes is important. Characteristics of optical transmittance against resistance with the optimal point of that relationship are presented in the paper. Moreover, dependency between arrangmenent of graphene nanoplatelets agglomerates and type of nanofillers is shown. Two groups of tested inks contain graphene nanoplatelets with different filler diameters. The third group contains carbon nanotubes. Described parameters are important for production process and results of analysis can be used by manufac- turer working with elastic electronics. Keywords: graphene nanoplatelets, carbon nanotubes, paint, transparency, resistance, spray coating, flexible electronic, agglomerates 1. INTRODUCTION Graphene is a promising material with many interesting properties. 1, 2 Monatomic layer of carbon atoms or- dered in a honeycomb lattice 3, 4 makes graphene a zero-gap semiconductor or a semi-metal. The combination of graphene’s unique optical and electrical properties and the absence of the bandgap (a single graphene layer) can be fully exploited in many applications. In photonics and optoelectronics it is used in solar cells, organic light- emitting devices, touch screens, photodetectors and ultrafast lasers. 1 Transparent and flexible electronic devices such as transistors, memory devices and integrated circuits have been demonstrated by introducing graphene electrodes and pentacene films or single-walled carbon nanotube (SWCNT) networks as active channels. 5 In several applications graphene has better properties than normally used materials (e.g. widely used ITO - indium tin oxide in transparent electrodes, is characterized by worse parameters like - brittleness and wear resistance, chemical durability and toxicity 2 ). Those advantages make grephene a fascinating material. Further author information: (Send correspondence to Zofia Lorenc) Zofia Lorenc: E-mail: lorenc@mchtr.pw.edu.pl, Telephone: +48 22 234 8442