Description of field of research:

Silicon heterojunction (HJT) solar cells have been recognized as one of the most prominent technologies to improve silicon solar cell power generation and they currently hold the silicon world-record efficiency of 26.7% for an interdigitated back-contact (IBC) based HJT cell. However, this cell architecture can suffer from reliability issues such as damp-heat (DH) or humidity-induced degradation (HID), resulting in severe power loss. Even though the efficiency of HJT cells exceeds other cell architectures, this failure mode has slowed the deployment of this technology to the market. Therefore, more studies on these related failures are required to pinpoint the root cause and mitigation approaches. The HID in other cell technologies, such as passivated emitter and rear cells (PERC), has been broadly studied; however, there have only been limited studies on HJT solar cells. Several failure modes have been realized in HJT modules after the damp heat test. However, due to the limitation of characterization tools and the influences of module packaging materials, the precise root cause of each failure mode remained unclear. Therefore, this work aims to develop a process that can generate similar failure modes in the non-encapsulated HJT cells, allowing more characterization to be done and thus confirm the root cause of each failure mode.


Photovoltaic and Renewable Energy Engineering

Research areas

Silicon heterojunction solar cell, Damp heat-induced degradation, Reliability of solar module, Humidity-induced degradation

The School of Photovoltaic and Renewable Energy Engineering not only offers world-class facilities for solar cell/modules design, fabrication and characterization, but it is also teaming with world-renowned researchers and dozens of PhD students who are always enthusiastic about sharing their knowledge and experience. The student will work closely with the supervisor, Dr. Chandany Sen, a postdoctoral research fellow and co-supervisor, Prof. Bram Hoex, and obtain great support from some cell/modules-reliability team members. Their research background is closely related to the project; therefore, they can guide the student's work in experimental and theoretical areas.

The student will participate in survey design, data analysis and reThe student undertaking this project will learn how to test the reliability of high-efficiency solar cells and modules currently available in the market. They will also learn how to characterize their performance to determine how much the power loss and failure modes are after the damp heat test.

After finishing this project, the student will become proficient in measurements of current-voltage, photoluminescence, electroluminescence, series resistance mapping, laser beam-induced current, quantum efficiency, and reflectance to analyze the failure modes in the solar modules and cells using industrial characterization tools.

The student will also be involved in developing a standard humidity testing process on the non-encapsulated cells to generate similar failure modes as on the modules, to allow more characterizing to be done and easily pinpoint the root causes of each failure mode.

It is not expected that a standard humidity test on the non-encapsulated cells will be achieved in this short period of time. However, it will become a stepping stone for further thesis projects and potentially PhD research topics.

The outputs of this research will lead to potential journal/conference publications.