ITO-Free Flexible Perovskite Solar Cells Based on Roll-to-Roll, Slot-Die Coated Silver Nanowire Electrodes

Abstract

For the roll to roll production of truly flexible, cost effective solar cells, alternatives are needed to replace indium tin oxide, which conventionally serves as the transparent electrode. In this work, silver nanowire/PEDOT:PSS based electrodes are processed onto PET substrates by a scalable, roll-to-roll slot-die process. These electrodes are extensively characterized and incorporated into ITO-free, flexible perovskite solar cells to achieve a champion efficiency of 11%, comparable to ITO controls on glass. Furthermore, all of the device layers, except the top electrode, were deposited under ambient conditions. Preliminary device bending tests showed negligible change in efficiency after 10 000 compressive bends to a 5 mm radius. This progress is key to the manufacture of cheap, flexible perovskite solar cells by low temperature processing techniques.

Emerging Novel Metal Electrodes for Photovoltaic Applications

“…The incorporation of Ag nanowire transparent electrode into a matrix of ITO film fabricated from sol–gel process has been demonstrated in PVSCs with improved stability . The fully embedment or coverage of metal transparent electrode by the conductive polymer with continuous film morphology is also helpful to the stability of metal transparent electrode, which has been realized through a slot die process for the formation of a thick PEDOT:PSS film on the Ag NW electrode . As shown in Figure e,f, the high‐performance and stable PVSCs have been demonstrated on the hybrid electrode of metal mesh and PH1000, which exhibit a high PCE of 14.0% and is highest among the metal‐oxide‐free flexible PVSCs .…”

Recent Advances of Device Components toward Efficient Flexible Perovskite Solar Cells

“…In addition, the poor adhesion of Ag‐NWs may bring down device efficiency. To circumvent these concerns, an intermediate layer composed of ZnO:F, graphene oxides (GOs), and PEDOT was placed between the Ag‐NW and perovskite layer . Deposition of amorphous aluminum‐doped zinc oxide (a‐AZO) layers also proved to significantly improve the chemical stability of Ag‐NWs .…”

Recent Progress of Flexible Perovskite Solar Cells

“…For example, bare Ag NWs networks were utilized as the top TCEs for FPSCs based on a Ti foil and a Cu foil . Since the rough surface of Ag NWs film usually hinders the improvement of device performance, some other transparent conductive components are introduced to fabricate Ag NWs‐based composite TCEs with smoother surface, such as Ag NWs/ZnO:F, Ag NWs/GO, and Ag NWs/PEDOT . Particularly, Ag‐mesh/PEDOT:PSS composite electrodes can be simply fabricated by spin‐coating PH1000 onto the flexible PET substrate with embedded Ag‐mesh, as shown in Figure a (the sheet resistance for this kind of composite TCE was reported to be as low as 1.2 ohm sq −1 ).…”