Hybrid crystalline-ITO/metal nanowire mesh transparent electrodes and their application for highly flexible perovskite solar cells

Abstract

Here, we propose crystalline indium tin oxide/metal nanowire composite electrode (c-ITO/metal NW-GFRHybrimer) films as a robust platform for flexible optoelectronic devices. A very thin c-ITO overcoating layer was introduced to the surface-embedded metal nanowire (NW) network. The c-ITO/metal NW-GFRHybrimer films exhibited outstanding mechanical flexibility, excellent optoelectrical properties and thermal/chemical robustness. Highly flexible and efficient metal halide perovskite solar cells were fabricated on the films. The devices on the c-ITO/AgNW-and c-ITO/CuNW-GFRHybrimer films exhibited power conversion efficiency values of 14.15% and 12.95%, respectively. A synergetic combination of the thin c-ITO layer and the metal NW mesh transparent conducting electrode will be beneficial for use in flexible optoelectronic applications.

Metal‐Nanowire‐Electrode‐Based Perovskite Solar Cells: Challenging Issues and New Opportunities

“…[97,99] As noted in Figure 9d-e, the incorporation of upper/lower conductive oxide layers of Al-doped zinc oxide (AZO) enabled efficient current collection in the area out of MeNW-networks, resulting in an improved areal charge collection. It is worth mentioning that the hybridization of MeNWs and conductive oxides gives the opportunity to achieve PSCs with device performances superior to those of their counterparts with a sole conductive oxide layer (Figure 9f,g), because MeNW-networks can act as ballistic electrical pathways, as illustrated in Figure 9d,e.…”

“…Owing to the presence of laterally vacant spaces between neighboring MeNWs, the intact contact is limited between highly conductive MeNWs and adjacent functional layers and hence, the collection of charge carriers is hampered when charge carriers cannot diffuse sufficiently over the cavities. [26,99] Such a phenomenon was visualized by the measurement of conductive AFM (c-AFM) for a single AgNW strand (Figure 9b-c). It clearly showed that the current only flows along the AgNW strand, while no current flow was observed in an outer region (Figure 9a,b), indicating that the cavity cannot collect charge carriers.…”

“…[86] Since MeNWs have been recognized to be appropriate for various solution-based deposition methods as listed in Section 2.2, it is conceivable that the integration of PSCs and MeNW-network electrodes would allow for all-solution-processable and high-throughput fabrication of PSCs. Currently, the technological maturity is seemingly at an early stage; the case studies, which fully address the expectations for MeNW-network-electrode-incorporated PSCs, have not been reported yet; however, the feasibility of replacing the conventional top [87][88][89][90][91][92][93][94][95] and bottom [96][97][98][99] electrodes with MeNW-network electrodes through a solution-based process has already been confirmed, and gradual advances are in progress with recent vigorous research on the materials and processing methods.…”

“…[15,129] Accordingly, several groups have made efforts to employ MeNW-network electrodes as a transparent electrode ( Table 2). [90,98,99,[130][131][132] Schematic illustrations of each type of PSC employing flexible MeNW-network electrodes are presented in Figure 6.…”

“…[99] The hybridized electrodes firmly retained their sheet resistance while the electrodes were subjected to mechanical, thermal, and chemical stresses. When the hybridized electrodes were employed in PSCs, the PCEs were as high as 14.15 and 12.95% for the cells with c-ITO/AgNWs and c-ITO/CuNWs hybrid electrodes, respectively (Figure 7b).…”