Page 141 - Multifunctional Photocatalytic Materials for Energy

Graphene-based nanomaterials 7

for solar cells

Syed Farooq Adil*, Mujeeb Khan*, Dharmalingam Kalpana †
†
* King Saud University, Riyadh, Saudi Arabia, CSIR—Central
Electrochemical Research Institute, Karaikudi, India

Graphene, an atomically thin two-dimensional carbonaceous material, has attracted
remarkable attention from scientists and technologists because of its excellent physi-
cochemical properties. Because of its exceptional electronic properties, such as high
electron mobility and high conductance by virtue of its zero band gap, graphene has
drawn particular attention to various types of solar cell applications, including dye-
sensitized solar cells (DSSCs) and organic, heterojunction, and perovskite solar cells.
Graphene also exhibits superior optical absorption properties, high mechanical strength,
and great flexibility and chemical stability. Because of these properties, graphene can
be used effectively as transparent conducting materials, transparent electrodes, catalytic
counter electrodes, electrolytes, and light harvesting materials in DSSC applications.
Numerous reports suggest that implementing graphene in respective components of
DSSCs could enhance the performance and efficiency of power conversion. For instance,
in organic solar cells, graphene can be used as electron acceptors and hole conductors.
In heterojunctions solar cells, it is used to form Schottky junctions with semiconduct-
ing materials (CdSe, and n-Si), which facilitates electron-hole separation and diffusions
driven by the built-in potential between graphene and semiconductors. Similarly, in
perovskite-type solar cells, graphene is applied as an electron-transporting photo electrode
and hole-transport layer material. Thus the introduction of graphene in various types of
solar cell applications creates an exciting pathway toward achieving highly efficient and
stable solar cells that can help obtain greater power conversion efficiency. Furthermore,
the combination of graphene with various materials, including different metals and metal
oxide nanoparticles, for solar cell applications not only maximizes practical applications
of DSSCs; it also enhances the synergetic effects between both of the active materials,
helps to increase the light-to-electricity conversion efficiency, and enhances the perfor-
mance of photoelectrochemical devices. Therefore graphene and graphene-based mate-
rials have emerged as a promising solution for the growing demand of fast-response and
energy-efficient applications in future energy conversion devices, including solar cells.

7.1 Introduction

Our modern lifestyle has significantly amplified the dependence on technology, which
over time has increased the demand for energy. However, conventional energy re-
sources (petroleum, coal, etc.) are limited and are being depleted at a fast rate; thus
Multifunctional Photocatalytic Materials for Energy. https://doi.org/10.1016/B978-0-08-101977-1.00008-9
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