Amorphous Silicon Thin Film Deposition for Poly-Si/SiO2 Contact Cells to Minimize Parasitic Absorption in the Near-Infrared Region

Abstract

Tunnel oxide passivated contact (TOPCon) solar cells are key emerging devices in the commercial silicon-solar-cell sector. It is essential to have a suitable bottom cell in perovskite/silicon tandem solar cells for commercial use, given that good candidates boost efficiency through increased voltage. This is due to low recombination loss through the use of polysilicon and tunneling oxides. Here, a thin amorphous silicon layer is proposed to reduce parasitic absorption in the near-infrared region (NIR) in TOPCon solar cells, when used as the bottom cell of a tandem solar-cell system. Lifetime measurements and optical microscopy (OM) revealed that modifying both the timing and temperature of the annealing step to crystalize amorphous silicon to polysilicon can improve solar cell performance. For tandem cell applications, absorption in the NIR was compared using a semitransparent perovskite cell as a filter. Taken together, we confirmed the positive results of thin poly-Si, and expect that this will improve the application of perovskite/silicon tandem solar cells.

Influence of Photonics and Plasmonics Effect on Ultrathin Amorphous Silicon Thin Film Solar Cell

“…Consequently, the light photons or plasmon interaction reduced with the dielectric or metallic nanostructure based solar cells and reported by various researchers [9][10]. Experimentally, the amorphous silicon solar cells can be fabricated by low temperatures (100-250°C) using plasma enhanced chemical vapor deposition (PECVD), and radio frequency PECVD techniques [11][12][13]. Further, these thin film and flexible solar cells are finding to use in various energy sectors such as automobiles, defense or energy storage devices [14].…”

Perovskite/Silicon Tandem Solar Cells: Choice of Bottom Devices and Recombination Layers

“…107,108 To achieve the formation of the doped poly-Si tunnel-junction, a precursor (i.e., a-Si:H) has been introduced. 109 The deposition of the a-Si:H layer is carried out by PECVD, and then the conversion of a-Si:H into poly-Si is achieved by annealing. Furthermore, the adoption of an a-Si:H precursor and the formation of poly-Si alleviate parasitic absorption in the near-infrared region (NIR) in TOPCon solar cells, suppressing recombination and enhancing voltage and current and thereby raising efficiency.…”

“…However, it is possible that the sputtering process for ITO damages the layer underneath and brings about a detrimental effect on the performance of tandem cells . Utilizing doped poly-Si as the recombination layer to form a poly-Si tunnel-junction can avoid the use of sputtering processes and therefore their damage (Figure b). , To achieve the formation of the doped poly-Si tunnel-junction, a precursor (i.e., a-Si:H) has been introduced . The deposition of the a-Si:H layer is carried out by PECVD, and then the conversion of a-Si:H into poly-Si is achieved by annealing.…”

Perovskite Tandem Solar Cell Technologies

“…In Ref. [5], entitled "Amorphous Silicon Thin Film Deposition for Poly-Si/SiO 2 Contact Cells to Minimize Parasitic Absorption in the Near-Infrared Region", Kang and Lee et al proposed a thin amorphous silicon layer to reduce parasitic absorption in the NIR region in TOPCon solar cells, which are the key emerging silicon photovoltaic technology in the commercial silicon photovoltaic market. The thin amorphous silicon layer can crystalize to polysilicon, and the thickness of poly-Si can dramatically affect the efficiency of perovskite/silicon tandem solar cells.…”