Inkjet printing of composite hole transport layers and bulk heterojunction structure for organic solar cells

Abstract

Thin solid films and inkjet printing technology have been investigated over a decade as being utilized for fabrication of an organic solar cell based on various nanomaterials such as carbon nanotube, graphene, fullerene, and macromolecules. Recent progress has shown its great potential to optimize the photovoltaic performances by means of inkjet printing. This paper presents the inkjet printing scheme to comprehensively fabricate the composite films and bulk heterojunction structures by varying solid concentration, droplet volume, and droplet spacing. As a result, it yielded a hole transport layer and a photoactive layer for the solar devices. The cell performances such as short-circuit current, open-circuit voltage, power conversion efficiency, series resistance, shunt resistance, fill factor, light dependence and stability were modelled, analyzed and evaluated in the study. A variety of composite films and materials fabricated by the scheme and nanomaterials could be applied in functional structures such as interfacial layers and electrodes for flexible solar cells in the future.