Performance improvement of thin-film silicon solar cells using transversal and longitudinal titanium nitride plasmonic nanogratings

Taking advantage of plasmonic nanostructures for light trapping in thin-film silicon solar cells has attracted ample attention among researchers. Titanium nitride (TiN) has recently been introduced as a promising material exhibiting plasmonic properties similar to gold while taking advantage of low cost, low loss, and CMOS compatibility. Moreover, utilization of TiN offers a good tunability since the optical properties of TiN depend on many fabrication parameters. In this work, transversal and longitudinal TiN nanograting arrays have been employed to act like perpendicular polarizers trapping the incident light in the active layer of the cell. Using optical and electrical simulations, it has been shown that the design provides a significant enhancement in the performance of thin-film silicon solar cells owing to the excitation of surface plasmon resonances and their resultant light trapping. Thanks to the employment of TiN nanogratings, the device offers a broadband absorption enhancement with a considerable improvement at the near infrared wavelengths in which the absorption of bare silicon layer is weak. The proposed thin-film cell results in short-circuit current and power conversion efficiency of about 26.46 mA/cm(2) and 12.27%, respectively proving the proficiency of the design for performance improvement of thin-film photovoltaic systems.