• Crystal structure, optical and electrical characteristics of rutile TiO₂ nanocrystallite-based photoanodes doped with GeO₂

• Fulltext

https://www.ias.ac.in/article/fulltext/boms/042/05/0252

• Keywords

TiO& #8322; nanocrystallites; rutile-type TiO& #8322; ; optical energy gap; refractive index; efﬁciency.

• Abstract

The effect of germanium dioxide, GeO₂ doping on dye-sensitized solar cell (DSSC) TiO₂ nanocrystallite photoanodes with composition (TiO₂–(GeO₂)_{$x$} :0 ≤ $x$ ≤ 0.3 wt%) has been studied. The pure sample and GeO₂-doped samples have been synthesized by a conventional solid-state reaction method and analysed by means of X-ray diffraction, scanning electron microscopy, energy dispersive X-ray and ultraviolet–visible spectroscopy techniques. The photovoltaic characteristics of the prepared samples have been studied by employing $J–V$ measurements. The pattern of XRD depicted that the dominating phase in the sample with $x$ = 0 is a rutile tetragonal phase with the P4₂/$mnm$ space group. An increase in GeO₂ concentration leads to an appearance and rise of another hexagonal phase structure of α-GeO₂ with the P3₂21 space group. Data obtained from the UV–visible spectroscopy measurements reﬂect that the optical energy gap ($E$^{optical}) increases with increasing GeO₂ content, while the optical refractive index decreases. $J–V$ photovoltaic characteristics conﬁrm that the DSSCs doped with low-concentration doping, $x$ = 0.05 and 0.1 of GeO₂ have higher values for conversion efﬁciency (η), ﬁll factor and short circuit current density ($J$_{sc}) compared with samples with high-concentration doping ($x$ = 0.2 and 0.3) of GeO₂. The present results showed that TiO₂–(GeO₂)_{$x$} ($x$ = 0.05 and 0.1 wt%) ﬁlms are potential candidates for optical ﬁlter materials and optoelectrical and photo-conversion energy devices.

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Volume 42 | Issue 6
December 2019

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Posted on July 25, 2019