High performance nanopillars array silicon solar cells

We report a novel plasmonics silicon solar cell design, with the possibility of lower cost and higher efficiency. The proposed solar cells consist of radial p-n junction silicon nanopillars array in combination with plasmonics metal nanoparticles on its surface. Simple and solution processible methods such as metal assisted electroless chemical etching (MACE) and Spin on Dopant (SOD) techniques were used for the fabrication of the described solar cells. Atomic layer deposition (ALD) grown aluminum oxide (Al₂O₃) was employed as an emitter surface passivation layer. Despite having the high surface to volume ratio of the nanopillar arrays textured surface, we observed an open circuit voltage (V_OC) and the short circuit current density (J_SC) as high as 572mV and 29.9mA/cm² respectively, which leads to the power conversion efficiency (PCE) in excess of 11.30%, for the optimized structure of the solar cells described herein. Unlike the optical performance, the electrical performance of the aforementioned solar cells, degrade with the increase in nanopillar height beyond 400 nm. Upon the incorporation of metallic nanoparticles to the previously fabricated nanopillar arrays, the power conversation efficiency of the combined structure was observed to decrease to 10.79%. This can be attributed due to a reduced open circuit voltage in spite of having a higher fill factor.