Congratulations to Donghao Liu




Our warmest congratulations to Donghao Liu on winning the top-10 Conference Award at the 12th International Conference on Silicon Photovoltaics. This is a noteworthy award since this conference comprises over 150 scientific contributions from all around the world. Donghao is very thankful to the conference organisers, the reviewers who assessed her work, and the sponsor Ron Sinton from Sinton Instruments for granting her this excellent award.

Donghao’s work in this conference concentrated on Hydrogen-Induced Contact Resistance in TOPCon and PERC Solar Cells. Tunnel oxide passivated contact (TOPCon) solar cells are gaining significant interest in the PV community, due to their potential to achieve higher efficiency than PERC cells. Recent studies have shown that TOPCon lifetime test structures can undergo severe firing-induced surface related degradation. Thermal processes at intermediate temperatures (300 °C – 500 °C) have been used to mitigate both LeTID and surface related degradation. In PERC cells, these thermal treatments have been shown to also induce significant reductions in fill factor (FF), due to an increase in series resistance. However, this phenomenon has not been investigated in n-type TOPCon cells. In this work, we show, for the first time, that hydrogen-induced contact resistance (HICR) observed in PERC cells is also present in TOPCon cells. By varying the temperature from 350 °C – 400 °C, we show that the temperature of the process is critically important in determining the extent of degradation. The response of PERC and TOPCon cells under varied temperatures was not identical, indicating that some aspect of the cell structure may modulate the rate of HICR.

His full work will be published as an invited special issue to Elsevier’s Journal of Solar Energy Materials and Solar Cells later in the year.