This report discusses the project results and lessons learnt to date for the UNSW Project, Hydrogenated and Hybrid Heterojunction p-type Silicon PV Cells.
Heterojunction solar cells currently hold the world record efficiency for silicon solar cells at 26.7%. However, to achieve the high-efficiency potential of this technology, expensive, high-quality n-type wafers are required. In addition, normal heterojunction solar cells have all processing performed at low temperatures, meaning that the devices do not benefit from defect-engineering methods that can improve material quality and are normally incorporated for conventional solar cell technologies using cheap p-type silicon wafers. Another key challenge is ensuring a high quality of surface passivation with the ultra-thin amorphous silicon heterojunction structures, and the movement of electrons throughout the device without excessive resistance, both of which reduce performance. All of these aspects undesirably add to the cost of heterojunction solar cells.