CIGS solar cell devices on steel substrates coated with Al-P-O inorganic materials for flexible applications

Flexible copper indium gallium diselenide (CIGS)-based solar cells are developed on stainless steel (STS) substrates covered with an insulating layer. We coated inorganic layer containing oxygen, aluminum, phosphorus, and negligible sodium (APO) on stainless steel (STS) by using slot-die coating method and studied its application prospects as a substrate for flexible devices. Surface morphology characterization of STS exhibited an improved flatness after the APO layer coating process. The characteristics of the solar cells fabricated on these insulating films are also evaluated. Although the insertion of the insulating layer does not influence the formation of the CIGS film and solar cell performance, a better uniformity in the current-voltage curve is obtained.