Thin‐film polyimide/indium tin oxide composites for photovoltaic applications

Abstract

Soluble polyimides were prepared from suitable monomers and were evaluated for their thermal and mechanical properties. The polymers were processed into films for use as supports for transparent, conductive indium tin oxide (ITO) layers. After deposition, annealing in vacuo at temperatures up to 4008C was performed to test the ability of the materials to endure typical device fabrication temperatures without damage to the ITO-coated polymeric substrate. The evolution of the structural, optical, and electrical characteristics with the annealing temperature was analyzed and compared with that of polymeric and conventional glass substrates as references. Polyimide 6F6F, synthesized from hexafluoroisopropylidene diphthalic dianhydride and hexafluoroisopropylidene dianiline, had optimal characteristics for photovoltaic applications, permitting the achievement of conductive, ITO-coated samples with optical transmission greater than 75% in the visible and nearinfrared wavelength ranges, without significant deterioration of their properties after vacuum annealing at temperatures up to 3508C.

Micromorphology analysis of sputtered indium tin oxide fabricated with variable ambient combinations

“…Surface texture characteristics of the samples under study: Sq -RMS surface roughness, Str -surface anisotropy ratio, D -fractal dimension, K -pseudo-topothesy, τc -corner frequency, dgrain -average grain diameter. This improved insight into the impact of the ambient on ITO growth provide a path to better material properties for applications including light emissions such as flat-panel displays and organic or polymer-based electronics [43,44], thin film photovoltaics [45][46][47][48], and smart windows to conserve energy [49][50].…”

Robustification of ITO nanolayer by surface‐functionalization of transparent biopolyimide substrates

“…Several researchers have attempted the thin-layer ITO deposition and acquired low sheet resistance. [12][13][14][15][16][17] However, adhesion of metals/metal-oxides directly to the polyimides is usually poor due to the inertness of the polyimide surfaces has been rarely addressed. Neat/non-activated polyimide normally causes the ITO coatings to be poorly adhered and easily cracked, blistered, or otherwise removed.…”

Study of conducting ITO thin film deposition on flexible polyimide substrate using spray pyrolysis

“…Traditionally, the fabrication of metal oxide used to be carried out on the glass or ceramic substrate, but this trend has been successfully replaced by the polymeric matrix owing to the outstanding adhesion at the interface [7] and cost effectiveness of the process [8]. Moreover, the polymeric support offers the advantage in weight, elasticity, fragility and flexibility [7].…”

“…Out of the varieties of polymeric materials available, polyimides are well known to show the most promising blend of the thermal and the mechanical properties [8]; consequently, they possess thermal stability, good filmforming ability, low dielectric constant [9], high chemical resistance, low coefficient of thermal expansion and high mechanical strength [10][11][12][13]. Polyimides are used as highperformance engineering plastics and are considered well applicable for high-performance material [14].…”