1 ISSN 0003-701X, Applied Solar Energy, 2020, Vol. 56, No. 1, pp. 1–12. © Allerton Press, Inc., 2020. Russian Text © The Author(s), 2020, published in Geliotekhnika, 2020, No. 1, pp. 7–21. Modelling and Parameters Extraction of Flexible Amorphous Silicon Solar Cell a-Si:H Mohamed Louzazni a, *, Ahmed Khouya a , Aurelian Crăciunescu b , Khalid Amechnoue a , and Marco Mussetta c a National School of Applied Sciences, Abdelmalek Essaadi University, Tangier, Morocco b Electrical Engineering Department, University Politehnica of Bucharest, Bucharest, Romania c Department of Energy, Politecnico di Milano, Milano, Italy *e-mail: louzazni@msn.com Received June 30, 2016; revised May 16, 2018; accepted November 8, 2019 Abstract—The precise of solar cell model parameters being the prerequisite for realizing accurate photovoltaic models. Hence, the parameters identification techniques have attracted immense interest over the years among the researchers. This paper proposes a modelling and prediction of electrical intrinsic parameter extraction method of flexible hydrogenated amorphous silicon a-Si:H solar cell, based on the meta-heuristic firefly algorithm (FA). The characteristics of solar cells are non-linear, multivariable and multi-modal and difficult to identifies the electrical intrinsic parameters by conventional and analytical methods with high accuracy. Recently, the firefly algorithm has attracted the attention to optimize the non-linear and complex systems, based on the flashing patterns and behaviour of firefly’s swarm. Besides, the proposed constrained objective function is derived from the current–voltage curve. It is the absolute errors between the experimen- tal and calculated current and voltage values. Furthermore, the obtained results of the proposed algorithm are compared with the results obtained by quasi-Newton method (Q-N) and self-organizing migrating algorithm (SOMA). Indeed, to validate the performance of the algorithm, the statistical analyses are carried out to mea- sure the accuracy of the estimated parameters. In the end, the theoretical results of the firefly algorithm show an excellent agreement with experimental data and more accurate compared to other compared techniques. Keywords: flexible amorphous silicon, solar cell, bio-inspired algorithms, firef ly algorithm, self-organizing migrating algorithm DOI: 10.3103/S0003701X20010090 INTRODUCTION Since the early 1990s, the hydrogenated flexible amorphous a-Si:H solar cell on thin plastic substrates are great, interest for a wide variety of engineering applications and researchers [1, 2]. The flexible amor- phous photovoltaic generator can be installed on curved surfaces, they are less likely to be damaged by mechanical friction and vibrations and are easier to install. These advantages could make it possible for mobile devices and various electric appliances to cover part of their power demand for solar energy. Even an integration of photovoltaic in clothes, umbrella also is attractive for aerospace applications and more becomes a reality [3, 4]. In 1998 Merten et al. [5] pro- pose an improved equivalent circuit model for hydro- genated flexible amorphous silicon a-Si:H solar cells and modules, based on conventional diode current- voltage, photocurrent source and a new term to repre- sent additional recombination losses in the i-layer of P–I–N junction. Later, in 2013 the model was extended into double diode model considering the Staebler–Wronski-effect of amorphous silicon [6]. The exponential nonlinearity of the current–volt- age equation of flexible amorphous silicon solar cell causes many difficulties in extraction of the parame- ters. Compared with other technologies of photovol- taic, the research on flexible amorphous silicon a-Si:H solar cell circuit model and extraction parame- ters is still comparatively rare. The main use of the solar cell and photovoltaic module parameters extraction is to estimate the current–voltage and power–voltage characteristics for the proper model- ling, simulation, design, sizing, performance assess- ment, and control of photovoltaic power schemes. An experimental investigation has presented to studies the electric current characteristics of a monocrystalline silicon solar cell at various solar radiation power levels [7]. Besides, an analytical optimization of current, voltage and power has been presented using Lagrange multiplier method [8]. In addition, the forecasting SOLAR ENGINEERING MATERIALS SCIENCE