Surface-plasmon-induced photoabsorption of Ag nanoparticle embedded a-Si solar cell Habibuddin Shaik a, * , U. Basavaraju b , S.N. Rachith a, c , M. Sundaramurthy d , Abdul Sattar Sheik e , G. Mohan Rao f a Center for Nanomaterials and MEMS, Nitte Meenakshi Institute of Technology, Yelahanka, Bangalore, Karnataka, 560064, India b Central Manufacturing Technology Institute, Bangalore, Karnataka, 560022, India c Department of Mechanical Engineering, Nitte Meenakshi Institute of Technology, Yelahanka, Bangalore, Karnataka, 560064, India d Indian Institute of Technology, Poowai, Bombay, Maharashtra, 400076, India e Department of Physics, Nitte Meenakshi Institute of Technology, Yelahanka, Bangalore, Karnataka, 560064, India f Plasma Processing Laboratory, Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, Karnataka, 560012, India article info Article history: Received 30 May 2017 Received in revised form 1 August 2017 Accepted 14 August 2017 Keywords: Light trapping Silver nanoparticles Solar cell Surface plasmons Amorphous silicon abstract Effect of silver nanoparticles on the performance of the solar cell is presented. We fabricated an amor- phous silicon solar cell with a high quality absorber layer, deposited by sputtering. We have investigated the quality variation in the absorber layer with three different power modes of sputtering. The effect of hydrogen incorporation on the bandgap, dark conductivity, photo conductivity and hence photo gain of absorber layer is studied for the three power modes of sputtering. Silver nanoparticles are embedded in the high quality absorber layer of the solar cell at a depth of 50 nm. We are able to visualize the effect of surface plasmon resonance in the vicinity of 625 nm. Along with the plasmon resonance we are able to visualize the scattering effects in the long wavelength regions. The effect of areal coverage of the silver nanoparticles inside the absorber layer on the transmittance, J-V characteristics and external quantum efficiency is reported. We are able to increase the light absorption in the weakly absorbing region of 600 e675 nm by incorporating silver nanoparticles. The transmission is reduced to 46.6%, and in the vicinity of 625 nm we achieved 10.2% higher external quantum efficiency than the reference device. © 2017 Published by Elsevier B.V. 1. Introduction Photovoltaics, a continuously emerging technology towards future energy production. To fully realize its potential it is always necessary to search for the ways to reduce the manufacturing costs of photovoltaic cells without compromising high efficiencies. Thin film solar cells offer the advantage of controlling the cost of solar cell as they are fabricated by thin layers of material. However, the thinner the absorber layer more the transmission losses are, which hampers the solar cell performance. Light trapping mechanism i.e. confining light within the active layer to have improved light ab- sorption, is becoming more crucial towards achieving high effi- ciencies. In wafer based solar cells i.e bulk crystalline silicon solar cells, enhancement in the absorption of light has been successfully observed and achieved by surface texturing [1]. However, this surface texturing has a little scope in thin film solar cells as the feature size of this texturing exceeds the typical thickness of the absorber layer of 300e2000 nm. To increase the short circuit cur- rent, researchers have employed surface texturing and in wave- length scale dimensions and are successful. This was possible by directing the incoming light into the PV cell at high propagation angles [2]. However, this hampers the cell performance as this technique promotes surface recombination. In the recent years, light trapping in solar cells by multiple scattering and localized surface plasmon resonance (LSPR) by embedded metal nanoparticles (NPs) has emerged as a novel approach [3e7]. A suitable wavelength of visible light can excite localized surface plasmon resonance (LSPR) in Silver (Ag) NPs. Ef- ficiencies enhancement in photo detectors and solar cell by incor- porating various metal NPs [8e11] is drawing tremendous interest in the field of photovoltaics. Enhancement in light absorption [12,13] is one of the key parameters for enhancing the efficiency of solar cell. These NPs which exhibits LSPR can be synthesized by various methods such as colloidal chemical methods [14], * Corresponding author. E-mail address: skhabibuddin@gmail.com (H. Shaik). Contents lists available at ScienceDirect Optical Materials journal homepage: www.elsevier.com/locate/optmat http://dx.doi.org/10.1016/j.optmat.2017.08.018 0925-3467/© 2017 Published by Elsevier B.V. Optical Materials 73 (2017) 179e187