Functional Multilayered Transparent Conducting Oxide Thin Films for Photovoltaic Devices

Abstract

In this study, we present a thermally stable multilayered transparent conducting oxide (TCO) functionalized for dye-sensitized solar cells (DSSCs). Nb-doped TiO2 (NTO) layers deposited on conventional Sn-doped In2O3 (ITO) substrates using pulsed laser deposition (PLD) enhanced the optical-to-electrical conversion efficiency of the DSSCs by as much as 17% compared to that of bare ITO-based DSSCs. The electrical properties and J−V characteristics of the multilayered NTO/ITO films showed that the improved cell performance was due to the facilitated charge injection from TiO2 to ITO that resulted from the formation of an ohmic contact with ITO, as well as the conserved high conductivity of ITO after the oxidizing annealing process. Moreover, the NTO/ITO-based DSSC exhibited higher efficiency than a F-doped SnO2(FTO)-based one, which demonstrates that optimization of multilayered NTO-based TCOs is a realistic approach for achieving highly efficient photoenergy conversion devices.

Improved‐Performance Dye‐Sensitized Solar Cells Using Nb‐Doped TiO2 Electrodes: Efficient Electron Injection and Transfer

“…Nb‐doped TiO 2 also has been shown to hold promising applications in transparent conducting oxides (TCOs),7, 8 antistatic materials, and gas sensors 9, 10. Recently, Fujishima and coworkers reported that a Nb‐doped TiO 2 (NTO) film could be used as a favorable electron‐transfer mediator in photovoltaic devices,11 which was further testified by other research groups 12–14. However, few studies have been reported on the positive role of Nb‐doped TiO 2 nanoparticles when applied as the photoanode material of DSSCs, and the mechanism of the effects caused by ion doping is still controversial.…”

Structural and Electrical Properties of Nb‐Doped Anatase TiO2 Nanowires by Electrospinning

“…Recent discovery of metallic conductivity and high optical transparency in Nb‐doped anatase TiO 2 (Nb:TiO 2 ) stimulated intense research on this material 33,34 for their applications as transparent conducting oxides 35–40 . The Nb 5+ is an n ‐type dopant for TiO 2 , modifies the band structure of TiO 2 , and generates additional carriers in its conduction band 34,41 .…”

“…[23][24][25][26][27][28][29][30][31][32] Recent discovery of metallic conductivity and high optical transparency in Nb-doped anatase TiO 2 (Nb:TiO 2 ) stimulated intense research on this material 33,34 for their applications as transparent conducting oxides. [35][36][37][38][39][40] The Nb 51 is an n-type dopant for TiO 2 , modifies the band structure of TiO 2 , and generates additional carriers in its conduction band. 34,41 The band structure calculations report that the 4d orbitals of Nb strongly hybridize with the 3d ones of Ti and form a d-natured conduction band, which is thought to be the origin of metallic conductivity in this material.…”

Application of Electrospun Nb:TiO₂ Nanofibers to Dye Sensitized Solar Cells

“…Then, the band bending at the interface between TiO 2 nanoparticles and NTO-NFs is expected to promote the carrier transfer at the interface [8,9]. In the present study, we added ES-NFs of TiO 2 and NTO to the dye-sensitized layer of mesoporous TiO 2 in conventional DSCs, and examined their effects to the photovoltaic characteristics.…”