TCAD based numerical exploration of industrially feasible tunnel oxide passivated contact on p-type silicon

• Published in: Solar energy Vol. 253; pp. 231 - 239
• Main Authors: Bhajipale, Jayshree, Kottantharayil, Anil, Sreejith, K.P.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-03-2023
• Subjects: Hole selective polysilicon contact; Industrial solar cells; p-type high efficiency solar cells; Sentaurus TCAD; Tunnel oxide passivated contacts; p-type high efficiency solar cells; Sentaurus TCAD; Tunnel oxide passivated contacts; Hole selective polysilicon contact; Industrial solar cells
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2023.02.040

Tunnel Oxide Passivated Contact (TOPCon) is considered as an immediate successor of Passivated Emitter and Rear Contact (PERC). Rear side full area hole selective passivating contact with front n+ diffused emitter on p-type silicon (Si) (p-TOPCon) would be an incremental upgrade from PERC. However, limited studies are present on p-type Si and most of them are on TOPCon with rear full area electron selective contact (n-TOPCon). In this work, we explore the potential of p-TOPCon by incorporating industry relevant material and process parameters in Sentaurus TCAD simulations. These include bulk lifetime (τb), wafer resistivity (ρ), polysilicon related rear parameters, front emitter sheet resistance (Rsheet) and its passivation (Sfront), and finger width (Wfinger). Simulation results are benchmarked against PERC and n-TOPCon. p-TOPCon outperforms PERC and has lower sensitivity to wider range of τb, ρ, and Sfront. Simulation suggests that an efficiency of 23.83% can be achieved for industrially feasible τb of 5 ms, ρ of 1 Ω-cm, emitter Rsheet of 132 Ω/sq, and Wfinger of 20μm for p-TOPCon. Replacement of diffused emitter with n-TOPCon would be ideal after accomplishing above anticipated advancements and in such a scenario, efficiency > 24.4% can be achieved on p-type Si.
•Potential of p-TOPCon for industrial application is presented using Sentaurus TCAD.•p-TOPCon is less sensitive to bulk and surface passivation properties than n-TOPCon.•p-TOPCon can offer efficiency up to 23.83% for industry relevant parameters.•Simulations suggest p-TOPCon can be the immediate successor of PERC.•Adoption of n-TOPCon over p-TOPCon further push the efficiency beyond 24.4%.