Preface

Silicon-based monocrystalline and multicrystalline solar cells are by far the most widely used solar cells today. Thin film technologies in general, and cadmium sulfide (CdS) and cadmium telluride (CdTe) in particular, are increasingly being employed. Other solar cells based on dyes or organic materials are still in their infancy but promise a bright future for more efficient photovoltaic technologies.

In photovoltaics, "thinness" generally refers to so-called first-generation, high-efficiency silicon cells, which are manufactured from bulk wafers hundreds of micrometers thick. Thin films sacrifice some light-gathering efficiency but use less material. In copper indium gallium diselenide (CIGS) solar cells, the efficiency tradeoff is less severe than in silicon. The record efficiencies for thin film CIGS cells are slightly less than those of CIGS for lab-scale top performance cells. In 2008, CIGS efficiency was by far the highest compared with those achieved by other thin film technologies such as CdTe photovoltaics or amorphous silicon (a-Si). CIS and CGS solar cells offer total area efficiencies of 15.0% and 9.5%, respectively. In 2015, the gap with the other thin film technologies was closed, with record cell efficiencies in laboratories of 21.5% for CdTe (FirstSolar) and 21.7% for CIGS (ZSW).

One material with a larger bandgap than Si is perovskite, which has been researched since 2009 for use in thin film solar cells. Starting with a 4% cell efficiency, perovskites have shown rapid progress, demonstrating a 10.9% efficient cell mid-2012 and increasing to as much as 17.9% in 2014. Perovskites are materials following the formula ABX3 where A and B are cations of different sizes and X is an anion.

Thin film-based solar cells that have the common processes for deposition of semiconducting materials with low thickness on different substrates giving uniform appearance produce modules of slightly lower efficiency. The market share for all these technologies is around 10% and remains relatively stable.

#### **Beddiaf Zaidi**

Faculty of Matter Sciences, Department of Physics, University of Batna 1, Batna, Algeria

#### **Chander Shekhar**

Department of Physics, Amity School of Applied Sciences, Amity University Gurgaon, Haryana, India

## **Chapter 1**

## Introductory Chapter: Thin Films Photovoltaics

*Beddiaf Zaidi and Chander Shekhar*

## **1. Introduction**

#### **1.1 Overview on thin films photovoltaic technologies**

Currently, the ever-increasing energy demand has put a strain on conventional energy sources resulting in a catastrophic increase in greenhouse gases and their effects a great cause of concern. This rapid growth in the energy-intensive hymen activities and the ill effects of use of conventional energy resources has pushed scientists to explore and use new renewable, non-polluting energies sources to meet the energy demand of society. Among the renewable energy resources are solar energy produced by photovoltaic panels, wind, geothermal, biomass, hydropower, etc. [1–6].

To tap the abundantly available solar energy especially in the tropics, among the variety of the materials employed amorphous thin-film silicon (a-Si) based solar cells has been mainly used [7]. Among other materials, CdTe (heterojunction cadmium telluride, cadmium sulphide), CIS (heterojunction of copper diselenide indium/cadmium sulfide) have also been used [8, 9]. The manufacturing of these materials is carried out largely in automated systems free or with minimal hymen interventions which is suitable for large-scale productions (**Figure 1**).

In addition to the traditional technologies to generate energy from renewable energy sources, many other approaches and avenues are currently opening up, with a lot of uncertainty that which of these may prove to be more effective over the other [10].

At present, crystalline technologies (multicrystalline and monocrystalline) are by far the most widely used. But "thin film" technologies in general and CIS and CdTe in particular, are increasingly developing being employed by more and more people. Whereas other approaches employing dyes or organic materials are still in their infancy. These approaches though promise a bright future for solar energy generation by photovoltaic cells. There are currently three large families/generations of solar cells as follows [11–14].


**Figure 1.** *Efficiencies of solar cells.*

• Photovoltaic polymer cells will be mentioned for information as their performance can still only be observed under experimental conditions and they only constitute a long-term alternative. We will also consider concentrators intended for power stations, intended to follow the solar race and permanently expose extremely expensive cells and with very high efficiency.

## **Author details**

Beddiaf Zaidi1 \* and Chander Shekhar2

1 Faculty of Matter Sciences, Department of Physics, University of Batna, Batna, Algeria

2 Department of Physics, Amity School of Applied Sciences, Amity University Gurgaon, Gurugram Haryana, India

\*Address all correspondence to: zbeddiaf@gmail.com

© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Introductory Chapter: Thin Films Photovoltaics DOI: http://dx.doi.org/10.5772/intechopen.102483*

## **References**

[1] Salameh ZM, Dagher F, Lynch WA. Step-down maximum power point tracker for photovoltaic systems. Solar Energy. 1991;**46**(5):279-282

[2] Zaidi B, Saouane I, Shekhar C. Simulation of single-diode equivalent model of polycrystalline silicon solar cells. International Journal of Materials Science and Applications. 2018;**7**:8-10

[3] Zaidi B, Saouane I, Madhava Rao MV, Li R, Hadjoudja B, Gagui S, et al. Matlab/simulink based simulation of monocrystalline silicon solar cells. International Journal of Materials Science and Applications. 2016;**5**:11-15

[4] Mrabti T, El Ouariachi M, Kassmi K, Olivié F, Bagui F. Amélioration du Fonctionnement des Systèmes Photovoltaïques suite aux Brusques Variations des conditions Météorologiques et de la charge. Revue des Energies Renouvelables. 2008; **11**(1):107-117

[5] Chisti Y. Biodiesel from microalgae. Biotechnology Advances. 2007;**25**(3): 294-306

[6] Zou Z, Ye J, Sayama K, Arakawa H. Direct splitting of water under visible light irradiation with an oxide semiconductor photocatalyst. Nature. 2001;**414**(6864):625-627

[7] Zaidi B, Belghit S, Shekhar C, Hadjoudja B, Chouial B. Impact of anti-reflective coating on the characteristics of a-Si: H solar cells. Nanosistemi Nanomateriali, Nanotehnologii. 2018;**16**:713-718

[8] Pudov AO, Kanevce A, Al-Thani H, Sites JR, Hasoon FS. Secondary barriers in CdS-CuIn1-xGaxSe2 solar cells. Journal of Applied Physics. 2005;**97**:1063

[9] Zaidi B, Zouagri M, Merad S, Shekhar C, Hadjoudja B, Chouial B. Boosting electrical performance of CIGS solar cells: Buffer layer effect. Acta Physica Polonica A. 2019;**136**:988-991

[10] Beaucarne G. Silicon thin-film solar cells. Advances in OptoElectronics. 2007;**2007**:1-12

[11] Available from: http://www. photovoltaique.info/Les-types-demodules

[12] Zaidi B. Introductory chapter: Introduction to photovoltaic effect. In: Solar Panels and Photovoltaic Materials. Rijeka: IntechOpen; 2018

[13] Zaidi B, Belghit S. Silicon Materials. Rijeka: IntechOpen; 2019

[14] Zaidi B. Solar Panels and Photovoltaic Materials. Rijeka: IntechOpen; 2018

## **Chapter 2**
