Graphene synthesis and application for solar cells

  • PDF / 1,434,777 Bytes
  • 21 Pages / 584.957 x 782.986 pts Page_size
  • 93 Downloads / 232 Views

DOWNLOAD

REPORT


Pitchaimuthu Sudhagar and Yong Soo Kang WCU Program, Department of Energy Engineering, Center for Next Generation Dye-sensitized Solar Cells, Hanyang University, Seoul 133-791, South Korea

Wonbong Choia) Department of Materials Science & Engineering, Department of Mechanical & Energy Engineering, University of North Texas, Denton, Texas 76203 (Received 6 August 2013; accepted 19 September 2013)

To date graphene and graphene-derived materials have created an immense research interests due to its extraordinary physical, chemical, and physiochemical properties, which delineated graphene as an outstanding material for future electronics, optics, and energy-harvesting devices. Typically, graphene has high mobility and optical transparency along with excellent mechanical properties and chemical inertness. Single-layer graphene exhibits ultrahigh optical transmissivity (;98%), which allows passing through wide range of light wave lengths, thus designated as an ever-reported material for an optically conducting window. Furthermore, graphene’s optical, electrical, and electrocatalytic properties can be tuned by applying different chemical functionalization protocols, which make it one of the most suitable candidates for advanced applications in optoelectronic and energy-harvesting devices. This review is intended to summarize the most important experimental results from the recent publications concerning the fascinating properties of graphene electrodes and their applications in various types of solar cells. Furthermore, the state of the art of different graphene synthesis processes and functionalization for the applications in solar cells are also discussed in this review.

I. INTRODUCTION

Graphene is a single atom, thick two-dimensional (2D) material, thus, exhibiting ;97.7% transmittance throughout the entire visible light spectrum. Additionally, graphene has a flat transmittance spectrum from the ultraviolet (UV) region to the long wave length infrared (IR) region, thus exhibiting a wide window that allows a comprehensive range of photon wave length passed through it. Unconditionally, except graphene, these combinations of remarkable optical properties are yet to be observed in any types of materials till date. Similarly, graphene has unusual electronic transport properties, which follows the characteristics of 2D Dirac fermions, quantum hall effects, Landau level quantization, and so on. Consequently, graphene’s free charges are immobile in one spatial dimension but mobile in other two dimensions, and thus, charge carrier mobility is ;106 cm2/V/s in free-standing graphene. Similarly, graphene also exhibits excellent mechanical and thermal properties (k ; 3000–5000 W/mK)1 a)

Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2013.297 J. Mater. Res., Vol. 29, No. 3, Feb 14, 2014

http://journals.cambridge.org

Downloaded: 16 May 2014

and chemical inertness. Hence, all these properties coupled with the optical properties put together graphene a stronger candidate for applications