**10. Conclusions**

The incorporation of polymeric photovoltaics into garments and textiles have been explored new inroads for potential use in ''intelligent clothing'' in more smart ways. Incorporation of organic solar cells into textiles has been realized encouraging performances. Stability issues need to be solved before commercialization of various photovoltaic textile manufacturing techniques. The functionality of the photovoltaic textiles does not limited by mechanical stability of photovoltaics. Polymer-based solar cell materials and manufacturing techniques

Flexible Photovoltaic Textiles for Smart Applications 67

[24] Kim WH, Ma¨kinen AJ, Nikolov N, Shashidhar R, Kim H, Kafafi ZH. Appl Phys Lett 80,

[25] Jonsson SKM, Birgerson J, Crispin X, Greczynski G, Osikowicz W, van der Gon AWD,

[26] Ouyang J, Xu Q, Chu C W, Yang Y,\*, Lib G, Shinar Joseph S On the mechanism of

[28] Könenkamp R., Boedecker,K. Lux-Steiner M. C., Poschenrieder M., Zenia F., Levy-

[31] Hoth, C.N., Choulis, S.A., Schilinsky, P. and Brabec, C.J. "High photovoltaic performance of inkjet printed polymer: fullerene blends" Advanced Materials, 19, 2007, 3973. [32] M Pagliaro, G Palmisano, and R Ciriminna "Flexible Solar Cells" WILEY-VCH Verlag

[33] Bundgaard E and Krebs F C Low band gap polymers for organic photovoltaics Solar

[34] Kroon R, Lenes M, Jan C. Paul H, Blom W. M, Boer B de "Small Bandgap Polymers for

[35] Rajahn M, Rakhlin M, Schubert M B "Amorphous and heterogeneous silicone based

[40] Bayinder M, Shapira O, Sayain Hazezewski D Viens J Abouraddy A F, Jounnopoulas A

[41] Verdenelli M, Parole S, Chassagneux F, Lettof J M, Vincent H and Scharff J P, J of Eur.

[48] Park S H, Choi H J,Lee S B, Lee S M L, Cho S E, Kim K H, Kim Y K, Kim M R and Lee J

[49] Ramiera J., Plummera C.J.G., Leterriera Y., Mansona J.-A.E.,\_, Eckertb B., and Gaudianab

[51] Bayindir M, Sorin F, Abouraddy A F, Viens J, Hart S D, Joannopoulus J D, Fink Y Nature

K "Fabrications and photovoltaic properties of dye-sensitized solar cells with electrospun poly(vinyl alcohol) nanofibers containing Ag nanoparticles"

R. "Mechanical integrity of dye-sensitized photovoltaic fibers" Renewable Energy 33

Organic Solar Cells (Polymer Material Development in the Last 5 Years)" Polymer

sulfonate ) film through solvent treatment" Polymer 45, 2004, 8443–8450

conductivity enhancement in poly(3,4-ethylenedioxythiophene) : poly(styrene

[23] Kim JY, Jung JH, Lee DE, Joo J. Synth Met 2002;126:311.

SalaneckWR, Fahlman M. Synth. Met 1, 2003;139:

GmbH & Co. KGaA, Weinheim, 2008, 98-119

Reviews, 48, (3), 2008 , 531 - 582

[36] Schubert MB, Werner J H, Mater. Today 9(42), 2006

[39] Gratzel M, Prog. Photovolt: Res. Appl. 8, 2000, 171

D and Fink Y Nature Mat. 4, 2005, 820

[44] Hu M S and Evans A G, Acta Mater, 37, 1998, 917

[46] Agrawal D C, Raj R, Acta Mater, 37, 1989, 1265

[43] Muller D, Fromm E Thin Mater. Solid Films 270, 1995, 411

Macromolecular Research 19(2), 2011, 142-146

[50] Hamedi M, Forchheimer R and Inganas O Nat Mat. 6, 2007, 357

[52] Yadav A, Schtein M, Pipe K P J of Power Sources 175, 2008, 909

films" MRS Proc. 664, 2001

Ceram. Soc. 23, 2003, 1207 [42] Xie C, Tong W, Acta Mater, 53, 2005, 477

(2008), 314–319

431, 2004, 826

Energy Materials and Solar Cells 91 (11), 2007, 954-985

[37] Drew C, Wang X Y, Senecal K, J of Macro. Mol. Sci Pure A 39, 2002, 1085 [38] Baps B, Eder K M, Konjuncu M, Key Eng. Mater. 206-213, 2002, 937

[45] Yang Q D, Thouless M D, Ward S M, J of Mech Phys Solids, 47, 1999, 1337

[47] Rochal G, Leterrier Y, Fayet P, Manson J Ae, Thin Solid Films 437,2003, 204

Clement C. and Wagner S., *Appl. Phys. Lett*., 77, 2575 (2000) [29] Boyle D. S., Govender K. and O'Brien P.*, Chem Commun.*, 1, 80 (2002) [30] http://www.caburn.com/resources/downloads/eVapcat.pdf

(2002), 3844.

[27] Grätzel M., *Nature*, 414, 338 (2001)

are suitable and applicable for flexible and non-transparent textiles, especially tapes and fibers, with transparent outer electrodes.

The manufactured photovoltaic fibres may also be utilized to manufacture functional yarns by spinning and then fabric by weaving and knitting. Fibres and yarns subjected to various mechanical stresses during spinning, weaving and knitting may possibly damage the coating layers of photovoltaic fibres. These sensitive and delicate structures must be protected by applying special protective layers by noble coating techniques to produce photovoltaic textiles. Photovoltaic tents, curtains, tarpaulins and roofing are available to utilize the solar power to generate electricity in more green and clean fashion.

### **11. References**


are suitable and applicable for flexible and non-transparent textiles, especially tapes and

The manufactured photovoltaic fibres may also be utilized to manufacture functional yarns by spinning and then fabric by weaving and knitting. Fibres and yarns subjected to various mechanical stresses during spinning, weaving and knitting may possibly damage the coating layers of photovoltaic fibres. These sensitive and delicate structures must be protected by applying special protective layers by noble coating techniques to produce photovoltaic textiles. Photovoltaic tents, curtains, tarpaulins and roofing are available to

utilize the solar power to generate electricity in more green and clean fashion.

[5] Gunes S, Beugebauer H and Saricftci N S Chem Rev. 107, 2007, 1324

and N. S. Sariciftci, Springer-Verlag, Heidelberg, 2003.

[6] Coakley KM, ,cGehee M D, Chem Mater. 16,2004,4533

Sariciftci, Taylor & Francis, London, 2005.

[1] Aernouts, T. 19th European Photovoltaics Conference, June 7–11, Paris, France, 2004.

[4] European photovoltaic Ind. Asso. Global market outlook for photovoltaic until 2012.

[7] Organic Photovoltaics: Mechanisms, Materials, and Devices, ed. S.-S. Sun and N. S.

[8] Organic Photovoltaics: Concepts and Realization, ed. C. J. Brabec, V. Dyakonov, J. Parisi

[11] Spanggaard, H. and Krebs, F.C. (2004) A brief history of the development of organic and polymeric photovoltaics. Solar Energy Materials and Solar Cells, 83, 125. [12] Granstrom, M., Petritsch, K., Arias, A.C., Lux, A., Andersson, M.R. and Friend, R.H. (1998) Laminated fabrication of polymeric photovoltaic diodes. Nature, 395, 257. [13] Yu J W, Chin B D, Kim J K and Kang N S Patent IPC8 Class: AH01L3100FI, USPC Class:

[14] http://www.coatema.de/ger/downloads/veroeffentlichungen/news/0701\_Textile%20

[15] Krebs F C., Fyenbo J and Jørgensen Mikkel "Product integration of compact roll-to-roll

[16] Krebs F C., Polymer solar cell modules prepared using roll-to-roll methods: Knife-over-

[17] Luo P, Zhu Cand Jiang G Preparation of CuInSe2 thin films by pulsed laser deposition

[18] Solar energy: the state of art Ed: Gordon J Pub: James and James Willium Road London, 2001 [19] Loewenstein T., Hastall A., Mingebach M., Zimmermann Y., Neudeck A. and

[21] Bedeloglua A,\*, Demirb A, Bozkurta Y, Sariciftci N S, Synthetic Metals 159 (2009) 2043–2048

Schlettwein D., *Phys. Chem. Chem. Phys.*, 2008, 10,1844.

[20] Lincot D. and Peulon S., *J. Electrochem. Soc.*, 1998, 145, 864.

[22] Pettersson LAA, Ghosh S, Inganas O. Org Electron 2002;3:143.

processed polymer solar cell modules: methods and manufacture using flexographic printing, slot-die coating and rotary screen printing" *J. Mater. Chem.*, 20, 2010, 8994-9001

edge coating, slot-die coating and screen printing Solar Energy Materials and Solar

the Cu–In alloy precursor and vacuum selenization, Solid State Communications,

transfer from a conducting polymer to buckminsterfullerene. Science, 258, 1992, 1474.

[9] Tang, C.W. Two-layer organic photovoltaic cell. Applied Physics Letters, 48, (1986) 183. [10] Sariciftci, N.S., Smilowitz, L., Heeger, A.J. and Wudl, F. (1992) photoinduced electron

fibers, with transparent outer electrodes.

[2] Lund P D Renewable energy 34, 2009, 53 [3] Yaksel I Renewable energy 4, 2008, 802

www.epia.org

136259, 2007

Month\_GB.pdf

Cells 93, (4), 2009, 465-475

146, (1-2), 2008, 57-60

**11. References** 


**4** 

*Bulgaria* 

**Dilute Nitride GaAsN** 

Malina Milanova1 and Petko Vitanov2 *1Central Laboratory of Applied Physics, BAS* 

**and InGaAsN Layers Grown by** 

**Low-Temperature Liquid-Phase Epitaxy** 

A critical goal for photovoltaic energy conversion is the development of high-efficiency, low cost photovoltaic structures which can reach the thermodynamic limit of solar energy conversion. New concepts aim to make better use of the solar spectrum than conventional single-gap cells currently do. In multijunction solar cells based on III-V heterostructures, better spectrum utilization is obtained by stacking several solar cells. These cells have achieved the highest efficiency among all other solar cells and have the theoretical potential to achieve efficiencies equivalent to or exceeding all other approaches. Record conversion efficiencies of 40.7 % (King, 2008) and 41,1 (Guter at al., 2009) under concentrated light for triple- junction allows hoping for practical realization of gianed values of efficiency in more multiplejunction structures. The expectations will be met , if suitable novel materials for intermediate cascades are found, and these materials are grown of an appropriate quality. Models indicate that higher efficiency would be obtained for 4-junction cells where 1.0 eV band gap cell is added in series to proven InGaP/GaAs/Ge triple-junction structures. Dilute nitride alloys such as GaInAsN, GaAsSbN provide a powerful tool for engineering the band gap and lattice constant of III-V alloys, due to their unique properties. They are promising novel materials for 4- and 5-junction solar cells performance. They exhibit strong bowing parameters and hold great potential to extend the wavelength further to the infrared part of

The incorporation of small quantity of nitrogen into GaAs causes a dramatic reduction of the band gap (Weyeres et al., 1992), but it also deteriorates the crystalline and optoelectronic properties of the dilute nitride materials, including reduction of the photoluminescence intensity and lifetime, reduction of electron mobility and increase in the background carrier concentration. Technologically, the incorporation probability of nitrogen in GaAs is very small and strongly depends on the growth conditions. GaAsN- based alloys and heterostructures are primarily grown by metaloorganic vapor-phase epitaxy (MOVPE) (Kurtz et all, 2000; Johnston et all, 2005)) and molecular-beam epitaxy (MBE) (Kurtz et al. 2002; Krispin et al, 2002; Khan et al, 2007), but the material quality has been inferior to that of GaAs. A peak internal quantum efficiency of 70 % is obtained for the solar cells grown by MOCVD (Kurtz et al. 1999). Internal quantum values near to unit are reported for p-i-n

**1. Introduction** 

the spectrum.

*2Central Laboratory of New Energy & New Energy Sources, BAS* 

