Improved preparation of AgNW film and its application in flexible counter electrodes of dye-sensitized and perovskite solar cells

Silver nanowire (AgNW) has been wildly used to prepare flexible conducting substrate of electronic and optoelectronic devices. By coating a layer of carbon onto a polymer/AgNW substrate, a counter electrode (CE) was obtained and it offers the advantages of high flexibility, light weight, low cost, simple fabrication, and operating efficiently in dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs). By modifying the traditional unidirectional roll-coating process of AgNW to cross-directional coating, the morphology and distribution of the AgNW network was improved, which led to increased transmittance and electroconductivity, and subsequently improved cell efficiency of DSSCs and PSCs. The performance of the CEs and solar cells was further promoted by optimized fabrication process of the carbon layer. The as-prepared flexible CEs achieved great enhancement of cell efficiencies, and maximum power conversion efficiencies of 5.17% and 14.32% were obtained by DSSCs and PSCs, respectively.