Boron‐doped polysilicon using spin‐on doping for high‐efficiency both‐side passivating contact silicon solar cells

Abstract

This study focuses on boron‐doped p+polysilicon (poly‐Si) passivating contacts using spin‐on doping (SOD). Experimental conditions, including annealing conditions, SOD concentration, and poly‐Si thickness, were controlled to improve passivation. Based on the analysis results, the passivation quality mainly changes with indiffusion and doping concentration, causing Auger recombination and field effects. Meanwhile, grain size also influences the passivation quality but showed marginal characteristics. Through further optimization using an etch back and diffusion barrier, the efficiency of the flat reference solar cell was improved to 17.5% with an open‐circuit voltage of 695 mV using a p+ poly‐Si contact emitter, the highest reported efficiency using SOD on saw‐damage‐etched surfaces. This study includes a detailed analysis of SOD p+ poly‐Si and shows promising results with potential for application in tandem devices. Furthermore, the cell efficiency is expected to increase by controlling the doping profile and application of textured surfaces, selective emitters, and forming gas annealing (FGA).

Titanium Silicide: A Promising Candidate of Recombination Layer for Perovskite/Tunnel Oxide Passivated Contact Silicon Two-Terminal Tandem Solar Cells

“… 26 Hence, utilizing a homojunction solar cell as the bottom cell is advantageous for the industrialization of tandem cells. Owing to their high-temperature tolerance, 27 , 28 TOPCon cells are fully compatible with the current manufacturing processes for PERC and highly efficient perovskite top cells. Reportedly, TOPCon cells have exhibited an efficiency of 26.7%, 12 indicating their potential as bottom cells in tandem solar cells.…”

Polysilicon-based tunnel junction Si solar cells with machine learning for tandem cell applications

“…it connects to the silicon wafer with low contact resistance and simultaneously provides surface passivation. In this study, we focused on high-temperature passivating contacts (HTPC) [11,12,13,14] and their integration into p + /n + SiCx tunnel junctions. These are considered a promising design for the bottom cell for several reasons: the optically preferred n-i-p configuration can be used for the top cell, they pose fewer limitations on top cell process temperature (permitting a broader choice for materials and processes), their high crystallinity ensures low parasitic absorption and high transverse conductivity, and different from TCO-based TJs, their deposition does not create sputter damage.…”