Applications of PEDOT:PSS in Solar Cells

Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is increasingly being used in the field of printed and flexible electronics in the form of electrode as well as intermediate layer. PEDOT:PSS belongs to the family of intrinsically conducting polymer materials whose members can conduct electricity in spite of their organic nature without the presence of metals. It is non-toxic, stable in the presence of air and humidity. Above all, it can be easily processed through conventional means. This chapter deals with the applications of PEDOT:PSS in organic solar cells (OSCs), dye sensitized solar cells (DSSCs) and silicon based hybrid solar cells. PEDOT:PSS is being used as electrode, buffer layer and hole conductive layer. It could manipulate the catalytic nature of counter electrode used in DSSCs. Whereas it may help to manipulate the morphological character in Si based hybrid solar cells along with enhancement of cell performance.

Introduction, Past and Present Scenario of Solar Cell Materials

Solar cells convert sunlight into electricity directly. It is a reliable, non-toxic and pollution free source of electricity. Since 19th century researchers have been trying to investigate different materials for solar cell devices. Commercially, Si based solar are predominate in this field, however, with passage of time different materials have been reported. Solar cell techniques are based on three different generations. 1st generation is based on Si and 2nd generation includes thin-films of CuInGaSe, GaAs, CdTe and GaInP etc. whereas 3rd generation is based on organic, hybrid perovskites, quantum dot (QD)-sensitizers & dye-sensitizers solar cells. Among all these, the 3rd generation solar cells are the most efficient and more cost effective than 1nd and 2nd generation solar cells. The 2nd generation is less costly but also less efficient compared to 1st generation. 3rd generation faces degradation of the photovoltaic materials which is a major problem. In this chapter different reported materials since 19th century for solar cells are mentioned. The past and present scenarios of solar cells are discussed comprehensively. It is observed that Si-based and multijunction solar cells dominate the market. Although, theoretically it is reported that hybrid perovskites and quantum dot materials for solar cell are the most efficient materials for photovoltaic PV devices. In spite of the high efficiency the stability of organic, hybrid perovskites, QD-sensitizers &dye-sensitizer materials is a big challenge.

Simulation Models for Solar Photovoltaic Materials

Semiconducting materials have dominated the photovoltaic industry for a long time. The advancement in solar cell technology is significantly influenced by computer modelling, designing and simulations of the semiconductor materials used for the device operation. Different modelling techniques including one, two and three dimensional models had been employed to comprehend the device operation of solar cell and other electronic devices based on semiconductor materials such as silicon and gallium arsenide. The performance of computing power is increasing with the passage of time in order to improve modelling and designing of different semiconductor materials for solar cell devices. In this chapter, different reported semiconductor materials, their standard characteristics and basic history of modelling, standard models used in photovoltaic industry and principles of modelling such as carrier statistics, transitions, band structure and mobility are explained in detail. Different characteristics of semiconductor material like the carrier transportation, carrier statistics, band structure, and heavy doping effect and carrier generations are described with respect to material modelling.

Hybrid Materials for Solar Cells

Solar energy is an attractive renewable energy source across the globe that can help overcome the energy crises and has the ability to replace conventional resources. Hybrid solar cells have higher conversion efficiency. In the current chapter the research related to the carbon nanotubes, organic and inorganic solar cell, dye-sensitized solar cells and tandem solar cells are reviewed. The organic solar cells are most suitable and economic, but it has low efficiency of up to 15%. The inorganic solar cells are very expensive and have high efficiency of up to 46% and are used in space applications. The hybrid solar cell is the third type and the perovskite tandem has already proven to be quite efficient (17%) and low cost, mostly because of the cheap materials that are being used.

Versatile Applications of Solar Cells

Solar cells have changed the way electricity is generated; it helps the world to reduce carbon emission, and consequently makes our electric grid system more resilient and reliable. Hence, this chapter presents the concept of solar cells and the basic principle of operation. The chapter also discusses materials in construction of solar cells including conventional semiconductors such as silicon and emerging/organic materials such as perovskite and quantum dots. Various applications of solar cells which include space research, telecommunications, grid connections, stand-alone connections and off-grid applications are also highlighted. Given the versatile application of solar cells, it is the future of electricity generation.

Solar Energy and its Multiple Applications

Solar energy is commercially exploited to provide benefits in the form of various products and capabilities applying a range of technologies. Electricity generation is achieved either directly from photovoltaic cells made of various materials or indirectly through the steam production from concentrating solar thermal systems. Whereas solar thermal power generation requires large scale plants, photovoltaic systems can be large or small in scale and building integrated, if required. Both types of generation can be standalone or connected to power grids. Solar energy is also extensively used for water and space heating, cooling and drying purposes. It can also be stored and/or transformed into a range of clean fuels and contributes energy to the manufacture of various energy-intensive products. The research into the artificial photosynthetic synthesis of biofuels although encouraging is, however, yet to be achieved commercially exploited on a large scale. Much scope remains for innovative technology breakthroughs to further improve the efficiency and uptake of all the solar energy technologies currently exploited or under investigation. Policy frameworks, renewable portfolio standards, feed-in tariffs and net-metering play an important and ongoing role in promoting the uptake of photovoltaics in particular.

Transparent Conducting Electrodes for Optoelectronic Devices: State-of-the-art and Perspectives

This chapter brings a concise review of the transparent conducting materials, films and electrodes (TCM, TCF and TCE, respectively), its state-of-the-art and outlooks ahead. Initial part of the chapter gives a general introduction of the topic, followed by a feasible road map as proposed and collated by the authors based on several other reviews. Fundamental physics behind the transparent conductors is discussed in the latter part. Established and potential oxide based TCMs, namely the transparent conducting oxides (TCOs) are reviewed which are being used commercially and will see application in the near future. Non-conventional TCMs, which are mostly non-TCOs, such as graphene, carbon nanotubes (CNT), metallic nanowires (MNWs) and their hybrids are described in brief. Scalability and large area fabrication which are most important concerns for commercialization of TCMs are discussed. The general prospects are given at the end.