Journal of Energy and Power Engineering 8 (2014) 107-111 ITO Etched by Photolithography Used in the Fabrication of Flexible Organic Solar Cells with PET Substrates Ourahmoun Ourida 1 , Belkaid Med Said 1 , Trigaud Thierry 2 and Shirr-Bonnans Martin 2 1. LATAGE (Laboratory of Advanced Technologies of Genie Electrics), Faculty of Electrical and Computer Engineering, UMMTO (Mouloud Mammeri University), Tizi-Ouzou BP 17 RP 15000, Algeria 2. MINACOM Laboratory, Limoges University, limoges cedex 87060, France Received: May 26, 2013 / Accepted: July 31, 2013 / Published: January 31, 2014. Abstract: In this study, the authors have shown the power conversion efficiency of flexible organic solar cells. The structure of the device is PET/ITO/PEDOT: PSS/P3HT: PCBM/Al. P3HT (poly-3-hexylthiophene). It was used as an electron donor, PCBM ([6, 6]-phenyl C61-butyric acid methyl ester) as an electron acceptor and PEDOT: PSS used as a HIL (hole injection layer). These materials were deposited by spin coating method on the flexible substrates. Photolithography method is used to etch ITO. The electrical parameters of the fabricated cells were investigated by means of J (V), FF (fill factor), the efficiency (η), photocurrent and IPCE measurement. It was observed that 45% of the absorbed photons are converted into current. The results obtained using etching technology by photolithography is better than that obtained in the clean room. Key words: Flexible substrate, PET, photolithography, organic solar cells, P3HT: PCBM. 1. Introduction Organic optoelectronic devices have been object of intense research in the last years, based on advantages as the possibility of producing large areas devices and the possibility to change the optoelectronic features of these materials without considerable changes in the process production [1]. PV (photovoltaic) cells are more and more attractive as clean renewable energy source and their lower fabrication cost and possibility of using flexible substrates [2]. To create an efficient PSC (polymer solar cell), it is necessary to optimize electricity generation, dissociation and carrier transport. The flexible solar cells fabricated using the roll-to-roll technology exhibited a power conversion efficiency of 1.88% [3]. Multilayer structure CIC (conductor-insulator-conductor) Corresponding author: Ourahmoun Ourida, Dr., research fields: LATAGE (Advanced Technologies of Electrical Engineering Laboratory). E-mail:ourahmourida@yahoo.fr. anode structure increases the photocurrent of the cells [4]. The argon ion treatments of the PET (polyethylene terephthalate) substrate improve the flexibility of the ITO (indium tin oxide) electrode [5]. The parameters of ITO such as resistivity, carrier concentration, transmittance, surface morphology and work function depend on the surface treatments and significantly influence the performances of the solar cells [6]. The internal quantum efficiency of a solar cell depends on its intrinsic material properties, such as its cristallinity, energy band gap, carrier transport behavior and the number of defects and impurities [7]. Thermal annealing improves photocurrent as well as interface between organic layers and metal electrodes due to the reduction of interface defects [8]. Several techniques are used to deposit the polymer layers onto flexible or glass substrates. Such as spin coating, doctor blading, printing, bruch painting, roll-to-roll-technology [8, 9] and rotogravure printing [10]. D DAVID PUBLISHING