Taiwan-based DelSolar announced today that it has signed an agreement to jointly develop copper zinc tin sulfur selenide (CZTS) thin film solar cells with IBM.

"This agreement is a significant step in the progress of our effort to create efficient solar cells using earth abundant materials with novel processes" said TC Chen, vice president of Science and Technology IBM Research. "We already have an excellent collaboration with Tokyo Ohka Kogyo (TOK) for developing manufacturing tooling and the chemistries required for this technology. Recently IBM demonstrated record solar cell efficiencies using a copper zinc tin sulfur selenide material. This new collaboration between DelSolar, TOK, and IBM now puts us firmly on the path to commercially viable technologies and processes for solar cells that could bring us closer to grid parity."

With the benefit of non-toxic and earth-abundant components, CZTS offers the benefits of broader spectrum sensitivity, lower working irradiance, broader temperature latitude and higher net power output. The light absorbing properties can also be fine-tuned by modifying the composition of the photovoltaic conversion layers. Light in weight, the new cell will also be flexible when used with a flexible base material.

Thin film solar cell technologies have been based earlier upon amorphous silicon, CdTe, and CIGS. This new technology is based upon inexpensive, earth abundant components, thereby circumventing the need for cadmium which is toxic, or materials whose availability may be questionable for the large volume growths anticipated in the future (indium or tellurium).

Until now, DelSolar has not engaged in thin film solar cell manufacturing partly because most of the commercially available technologies are of low efficiency or contain expensive materials or elements of limited projected availability. In addition, most of the current compound thin film solar cells on the market still use cadmium as the photovoltaic conversion layer or buffer layer.