A High-Quality Dopant-Free Electron-Selective Passivating Contact Made from Ultra-Low Concentration Water Solution

Crystalline silicon solar cells produced by doping processes have intrinsic shortages of high Auger recombination and/or severe parasitic optical absorption. Dopant-free carrier-selective contacts (DF-CSCs) are alternative routines for the next generation of highly efficient solar cells. However, it is difficult to achieve both good passivating and low contact resistivity for most DF-CSCs. In this paper, a high-quality dopant-free electron-selective passivating contact made from ultra-low concentration water solution is reported. Both low recombination current (J(0)) similar to 10 fA/cm(2) and low contact resistivity (rho(c) ) similar to 31 m Omega.cm(2) are demonstrated with this novel contact on intrinsic amorphous silicon thin film passivated n-Si. The electron selectivity is attributed to relieving of the interfacial Fermi level pinning because of dielectric properties (decaying of the metal-induced gap states (MIGS)). The full-area implementation of the novel passivating contact shows 20.4% efficiency on a prototype solar cell without an advanced lithography process. Our findings offer a very simple, cost-effective, and efficient solution for future semiconductor devices, including photovoltaics and thin-film transistors.

Automated summary

This study reports a high-quality dopant-free electron-selective passivating contact made from ultra-low concentration water solution. Both low recombination current and low contact resistivity are achieved on intrinsic amorphous silicon thin film passivated n-Si using this new contact. The full-area implementation of the novel passivating contact shows 20.4% efficiency on a prototype solar cell without advanced lithography process.