UNSW has received a funding grant from ARENA to conduct a project targeting reduced solar cell cost, achieved by improving the efficiency with which they convert sunlight into electricity. Improved efficiency reduces cost by reducing the area required for a given power output, reducing the cost of encapsulation, transport and installation for a given power. This is why the whole industry is presently switching to an earlier generation of UNSW cell technology known as the PERC cell, which will allow cell efficiency to be increased to a standard value of about 25% within 5 -10 years.
To reduce costs once this efficiency is standard, the most viable approach is to further boost efficiency by stacking thin cells made from another material onto the top surface of a silicon cell. One overlying cell eventually will allow 25% efficiency to be increased to 35%, two overlying cells to 40%.
The Efficient Adamantine Thin-Film on Silicon Tandem Cells project involves finding suitable materials for these overlying cells that are stable, non-toxic and abundant with the search to focus on materials that have the same crystal structure as silicon and diamond (adamantine semiconductors), since this increases prospects for success. Prospects are further boosted by UNSW’s recent discovery and patenting of 10 new adamantine semiconductor families.
How the project works
Building on exploratory studies completed in 2017, the project involves 5 strands: (1) Material identification/evaluation; (2) Cell fabrication/performance optimisation; (3) Integration with silicon cells; (4) Accelerated testing of candidate materials/devices; and (5) Development of practical manufacturing candidate sequences and their costing, together with development of a sequence capable of implementation on the UNSW SIRF (Solar Industrial Research Facility) pilot line.
Area of innovation
The Efficient Adamantine Thin-Film on Silicon Tandem Cells project is unique internationally in terms of the materials to be investigated. If successful, it would be the first worldwide to identify stable, non-toxic, abundant materials for this application.
The project will increase knowledge about suitability for different semiconductors for stacking onto silicon and, if successful, will identify new materials suitable for commercial use and future TW-scale deployment, as well as manufacturing sequences for high efficiency cells using these materials.
Read more about solar PV.