Numerical analysis of p-type and n-type based carrier-selective contact solar cells with tunneling oxide thickness and bulk properties

Abstract

Tunnel Oxide Passivated Contact (TOPCon) is a c-Si solar cell structure with tunneling oxide near the rear electrode. A full-area tunneling oxide provides sufficient passivation and low internal resistance with 1D carrier transport. Carrier tunneling mechanism is the key factor of a TOPCon solar cell; the thicker the tunneling oxide, the better is its ability to prevent minority-carrier tunneling. However, excessively thick oxide degrades majority-carrier tunneling. Therefore, the relationship between tunneling oxide thickness and cell performance is important. In this study, TOPCon solar cell structures are evaluated by varying their tunneling oxide thickness and bulk properties for both p-type and n-type bulk using numerical simulation. It is observed that the difference in bulk type is crucial to TOPCon solar cell performance: n-type material shows better performance because of its smaller minority-carrier tunneling current density and wider range of effective tunneling oxide thickness compared to p-type.

Review: Numerical simulation approaches of crystalline‐Si photovoltaics

“…The carrier tunnel transport model at the Si/tunnel‐oxide interface is required for modeling TOPCons (see Figure 3B). To express the tunneling current, the direct tunneling model 103 is used, 104 with dielectric constant $${\varepsilon }_{ox}$$, carrier effective masses $${m}_{e,h}$$, and barrier heights at the interface $${\rm{\Delta }}{{\rm{\Phi }}}_{C,V}$$ as the input parameters. Here, the use of the direct tunneling model assumes the uniform formation of the tunneling layer as the trapezoidal barrier is estimated, which the TOPCon will be applicable.…”

AFORS-HET-based numerical exploration of tunnel oxide passivated contact solar cells incorporating n- and p-type silicon substrates

“…TCAD simulations have examined the impact of tunnelling oxide thickness and bulk properties on p-TOPCon cell performance. 33 Gao et al reported a simulation study of a 22.40% p-TOPCon structure using the Quokka software with industrial-grade process parameters. 34 A logical, numerical study is mandatory for a deeper knowledge of significant factors that influence how well the devices perform.…”

Design Rule of Electron- and Hole-Selective Contacts for Polycrystalline Silicon-Based Passivating Contact Solar Cells

“…As aforementioned, poly-Si/SiO x structured electron and hole contacts exhibit different carrier transport mechanisms. − ,,,,− Figure b,c shows the transport behaviors of photogenerated electrons and holes in their respective contacts. In electron contacts, photogenerated electrons are collected through SiO x , as schematically shown in Figure b.…”