J Comput Electron DOI 10.1007/s10825-014-0652-2 Textured window with DLAR coating design for an effective minimization of electrical and optical losses in an efficient III–V solar cell Khomdram Jolson Singh · N. Basanta Singh · Subir Kumar Sarkar © Springer Science+Business Media New York 2014 Abstract Performances of solar cells with different win- dow materials and structures have been analysed and com- pared. Four different materials with varied thickness have been used for comparison. An efficient thin textured win- dow layer design with double layer anti reflection coating for III–V solar cell is then proposed. The optimum window is obtained with 18 nm InAlP material and further optimized with four sided textured surface coated with 125 nm double antireflective layer of Al 2 O 3 –TiO 2 . Our design shows mini- mum reflection and absorption loss in the wavelength range of 200–650 nm and better transmission for rest of the higher wavelength when illuminated with AM1.5G spectrum. Per- formance variation with different doping concentration on this layer is also investigated. At about 1 × 10 17 cm -3 car- rier concentration, EQE of the cell is found to be well above 95 %. The model has been validated with experimental data available from various recent literatures. Keywords Reflection loss · Recombination loss · Double layer anti-reflection coating (DLAR) · External quantum efficiency (EQE) · Athena · Atlas 1 Introduction Solar cells manufactured through industrial process have effi- ciencies of the order 10–15 % . This clearly shows about 90– K. J. Singh (B ) · N. B. Singh Department of Electronics and Communication Engineering, Manipur Institute of Technology, Imphal 795004, India e-mail: jolly4u2@rediffmail.com S. K. Sarkar Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata 700032, India e-mail: su_sircir@yahoo.co.in 85 % losses occur in solar cells [1, 2]. If these losses are min- imized, efficiency can be improved. Therefore, it becomes necessary to study different losses that occur in the solar cells and the methods which can be implemented to reduce them. Some practices which are followed to reduce the losses are better material selection, changing design procedure of the cell or proper manufacturing techniques. The window layer of solar cell is the region where the light starts to enter the whole cell and affect its performances. Even, some recent development has shown experimentally that the light trapping in nanowire (NW) arrays in window layer could enhance con- siderably the optical path length in the NW array based solar cell thereby increasing cell performance [3, 4]. For every solar cell, a wide band gap heterolayer is usually added to the front face to favour transparency and to passivate the emit- ter. Whether the cell is either single or multi-junction, the optimization of this extra front layer regarding losses is very important as it influences the optical and electrical behaviour of the device. Therefore, we feel the importance to focus on the analysis of this layer and investigate some useful meth- ods to minimize its losses. Therefore, in this work a detailed review of different losses that occur in the window layer is performed. From different material (AlGaAs, AlAs, InAlP, InAlGaP) with varied thickness have been used for the com- parison. 2 Material and methods 2.1 Selection of window materials The structures of III–V solar cell result from the epitaxial growth of numerous thin layers of different semiconductors. At the front side some of these layers could be part of the optical design that minimizes the reflection losses. In fact, 123