Multi-pulsed flash light sintering of copper nanoparticle pastes on silicon wafer for highly-conductive copper electrodes in crystalline silicon solar cells.

Graphical abstract Scalable Flash White Light (FWL) sintering of copper nanoparticles on silicon wafer is used to create highly conductive electrodes for crystalline silicon solar cells. After 1 s of FWL sintering, the Cu electrode has high electrical conductivity with lower cost, and no thermal damage, as compared to the state-of-the-art. Highlights • A new way to fabricate Cu electrodes using flash white light is demonstrated. • Flash white light sintering process is dramatically simple and high speed process. • Multi-pulsed FWL sintering method was developed for crystalline Si solar cells. • Artificial oxidation treatment improves the FWL sintering of Cu NPs on Si wafer. • Highly conductive Cu films were successfully produced under ambient conditions. Abstract In this work, ultra-high speed flash white light (FWL) sintering method of copper nanoparticle pastes on silicon wafer substrate, was developed to produce highly conductive and low-cost copper electrodes for crystalline silicon solar cells. FWL sintering of copper nanoparticles on silicon wafer substrate has been regarded to be very difficult, due to its high thermal conductivity (k) compared with that of polymer (PI and PET) substrates. To overcome this limitation, we applied multiple pulsed FWL to sinter copper nanoparticles (Cu NPs) printed on silicon wafer. Furthermore, bimodal Cu NPs with different size were also applied to enhance the packing density of Cu films for highly conductive Cu electrodes. Finally, this work demonstrated that Cu NP-pastes are successfully sintered on crystalline silicon wafer substrate by multiple pulsed FWL irradiations. [ABSTRACT FROM AUTHOR]