Morphological and opto-electrical properties of a solution deposited platinum counter electrode for low cost dye sensitized solar cells

Abstract

Although platinum (Pt) is a rare and very expensive material, Pt counter electrodes are still very commonly used for reaching high efficiencies in dye-sensitized solar cells (DSCs). The use of alternative cheaper catalyst materials did not yet yield equivalent efficiencies. In this work, we tried to understand how to reduce the amount of deposited Pt-material and simultaneously deliver higher DSC performances. We systematically compared the properties of Pt-counter electrodes prepared by simple solution deposition methods such as spray-coating, dip-coating, brushing with reference to the Pt-electrodes prepared by sputtering onto fluorine doped-tin oxides (FTOs). The morphological and structural characterizations of the deposited Pt-layers were performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The composition of Pt-material was quantified using SEM electron dispersive X-ray (EDX) mapping measurements which were further compared with optical transmission measurements. Also contact angle and sheet resistance measurements were performed. By taking Pt-layers composition, morphology and structural factors into account, 9.16% efficient N3 dye based DSCs were assembled. The DSCs were subjected to various opto-electrical characterization techniques like current-voltage (I-V), external quantum efficiency (EQE), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and transient photo voltage (TPV) measurements. The obtained experimental data suggest that the Pt counter electrodes prepared by solution deposition methods can also reach high DSC device performances with a consumption of very little amount of Pt material as compared with sputtered Pt-layers. This process also proves that higher DSC performances are not limited to the usage of sputtered Pt-layer as counter electrode.

Theoretical design and experimental synthesis of counter electrode for dye-sensitized solar cells: Amino-functionalized graphene

“…Commonly, Pt (deposited on conductive substrate) is used as CE in DSCs. Although Pt has high catalytic activity and good conductivity, the limited reserve and high price hinder the large-scale production of DSCs [6][7][8][9][10] . Therefore, finding economical CE materials to replace Pt is meaningful.…”

Waveguide solar concentrator design with spectrally separated light

“…2. External quantum efficiencies (Thalluri et al, 2013) of the N3 dye-sensitized solar cell (blue curve) and the SQ2 dye-sensitized solar cell (red curve) (Thalluri et al, 2013(Thalluri et al, , 2015. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.…”

“…Spectral solar cell properties used for the optical design come from GREENMAT d , according to previous published works (Thalluri et al, 2013(Thalluri et al, , 2015, briefly described in Section 6.1. Respectively, these dyes have high external quantum efficiencies (EQEs) in spectral a band-pass from 400 nm to 600 nm and 600 nm to 700 nm, as depicted in Fig.…”

“…The DSSCs with N3 and SQ2 dyes are prepared according to previous published works (Thalluri et al, 2013(Thalluri et al, , 2015. Photovoltaic current-voltage (I-V) performances were recorded by a class A solar simulator supplied by Newport Spectra Physics coupled with a Keithley 2400 Source meter under simulated 0.77 sun illumination (see Fig.…”