Silicon solar cells can achieve a better than 20% efficiency using a technology called IBC (interdigitated back-contact). A group led by Imec have demonstrated 23.3% efficiency on a small-area cell.
“The results prove the relevance of the IBC technology to our industrial partners,” says Jef Poortmans, director of Imec’s photovoltaic R&D programme, “such high efficiencies on small-area IBC silicon solar cells are a perfect base for further developing a large-area and industrially feasible IBC cell technology at Imec,”
Imec’s industrial partners in the IBC research are: Schott Solar, Total, Photovoltech, GDF-SUEZ, Solland Solar, Kaneka and Dow Corning.
IBC should reduce cell thickness, simplify module fabrication and improve the look of solar cell modules.
Key aspects of the 2×2 cm2 IBC cells are the n-type base float-zone (FZ) silicon substrates, a random pyramid texture, a boron diffused emitter, phosphorous diffused front- and back surface fields, a thermally grown silicon dioxide for surface passivation, a SiN single layer anti-reflective coating, lithography based patterning and Aluminum metallization.