IBM researches have recently established a new efficiency record for solar cells made of cheap materials and they were very near to the level of commercial solar panels. They managed to increase the efficiency with almost 40% of their solar cells, from 6,7 percent to 9,6 percent. To reduce even more the costs, these solar cells are build with an inexpensive ink-based process.
The new cell’s semiconductor material is made of abundant elements like copper, zinc, tin, and sulfur but as well as a relatively rare element selenium (CZTS).
Why can CZTS cells become the future of solar power? Well the IBM solar cell could easily become an alternative to thin film solar cells. This film solar cells use materials that are able to absorb very easily light, and the leading thin film manufacturer uses tellurium.
Tellurium is a very rare element, compared with selenium, which will not be able to sustain the needs of a growing energy demand and for sure it will need an urgent replacement. Even though selenium is very rare compared to gallium or indium, IBM’s solar cell could still compete with copper indium gallium and selenium cells (CIGS). The reason is that selenium is much cheaper than indium and gallium.
The ink-based manufacturing process solves not only the costs issue of CZTS cells but the efficiency problem as well. To make the cells a commercial solution, the efficiency needs to be increased in the lab to at least 12-15 percent, in order to make the manufacturers confident they will reach at least 10 percent efficiency. The 15% efficiency should be easily reachable either by improving other parts of the solar cell besides the main CZTS material, or by doping the semiconductor with other trace elements.