Luminescent Downshifting Silicon Quantum Dots for Performance Enhancement of Polycrystalline Silicon Solar Cells

Silicon quantum dots (Si-QDs) with luminescent downshifting properties have been used for the efficiency enhancement of solar cells. In this study, Phenylacetylene-capped silicon quantum dots (PA Si-QDs) have been fabricated and applied as luminescent downshifting material on polycrystalline silicon solar cells, by dropcasting. The PA Si-QD coated solar cell samples presented an average increase in the short circuit current (Isc) of 0.75% and 1.06% for depositions of 0.15 mg and 0.01 mg on 39 mm x 39 mm pc-Si solar cells, respectively. The increase was further enhanced by full encapsulation of the sample leading to overall improved performance of about 3.4% in terms of Isc and 4.1% in terms of power output (Pm) when compared to the performance of fully encapsulated reference samples. The PA Si-QD coating achieved a reduction in specular reflectance at 377 nm of 61.8%, and in diffuse reflectance of 44.4%. The increase observed in the Isc and Pm is a promising indicator for the use of PA Si-QDs as luminescent downshifting material to improve the power conversion efficiency of pc-Si solar cells.

Automated summary

Silicon quantum dots have been used to enhance the efficiency of solar cells. In this study, Phenylacetylene-capped silicon quantum dots were fabricated and applied as luminescent downshifting material on polycrystalline silicon solar cells. The coated solar cell samples showed an increase in short circuit current and power output, with a further enhancement achieved by full encapsulation of the samples. The reduction in specular and diffuse reflectance indicates the potential of Phenylacetylene-capped silicon quantum dots as luminescent downshifting material for improving power conversion efficiency of solar cells.