Photocurrent Performance and Nanostructure Analysis of TiO[sub 2]/ITO Electrodes Prepared Using Reactive Sputtering

Abstract

A systematic study of the photocurrent activity and the nanostructure of a TiO 2 indium tin oxide ͑ITO͒ electrode prepared using reactive sputtering was carried out. The photocurrent was measured in 0.1 M NaClO 4 aqueous solution using an amperometric method under irradiation. The total conversion efficiency (eff) was estimated. Various photoelectrode TiO 2 films were synthesized by controlling deposition times, sputtering powers, total pressures, and the mole percentage of oxygen used in reactive sputtering. The physical properties of the TiO 2 film such as the crystal phase, particle size, bandgap energy, and thickness were characterized using X-ray diffraction ͑XRD͒, scanning electron microscopy ͑SEM͒, UV-visible spectroscopy, and profilometry. The results indicated that the optimal photocurrent was obtained at a thickness of approximately 1.2 m and mean particle size of approximately 50 nm. The ͑112͒-preferred orientation anatase shows higher photocurrent than ͑101͒-orientation anatase due to its regular columnar structure. The phase diagram of the prepared TiO 2 film defined by sputtering power and total pressure was also studied.

Intrinsic Nitrogen‐doped CVD‐grown TiO2 Thin Films from All‐N‐coordinated Ti Precursors for Photoelectrochemical Applications

“…In contrast, the film from 2 at 600 °C (Fig. 5b inset) shows columnar structure which, also due to its higher thickness, enhances the light harvesting and facilitates the transport of photogenerated electrons to the underlying ITO substrate 32. From the NRA results, the film from 1 at 600 °C contains a higher carbon ratio than the film from 2 at 600 °C and obtains about 30 times less photocurrent response at 1.5 V vs. Ag/AgCl.…”

Thermal conduction effects impacting morphology during synthesis of columnar nanostructured TiO2 thin films

“…21,22 A number of deposition techniques have been employed to immobilize TiO 2 with 1D orientation onto a substrate. 11,12,17,[23][24][25][26][27][28] The recently developed aerosol-chemical vapor deposition (ACVD) process 9 to synthesize metal oxide films with columnar morphologies has several significant advantages over other existing methods. Since ACVD is a one-step process that operates at ambient pressure, the system is an economically viable process that can readily be scaled-up.…”

Rapid synthesis of nanostructured metal-oxide films for solar energy applications by a flame aerosol reactor (FLAR)

“…Titanium dioxide also has a prominent role as the electron conducting layer in photovoltaic dyesensitized solar cells 4 . For watersplitting and photovoltaics, morphology has repeatedly been identified as a critical, often efficiency-limiting physical characteristic of TiO 2 films [4][5][6][7] . To improve performance, it is essential to control the film morphology, which is ultimately determined by the synthesis process.…”