Enhancement of Dye‐sensitized Solar Cells Efficiency Using Graphene Quantum Dots as Photoanode

Abstract

Dye-sensitized solar cell (DSSC) is a candidate to substitute conventional photovoltaic devices due to efficiency, cost in comparison with silicon devices. In this report, graphene quantum dots have attracted considerable potential merit for the development of photo-electrodes of dye-sensitized photovoltaic cells. The incorporation of graphene quantum dots into DSSCs photo-electrodes induced lower recombination, enhanced electron transport, increased light scattering. The conventional semiconductor quantum dots usually has surface defect and instable. To overcome such limitations, we have developed a hydrothermal synthesis process fabricating graphene quantum dots (GQD) with strong visible range emission. The reduced GOs graphene oxide (RGO) underwent sonication, heating, filtering, and dialysis producing GQD. Various sizes of GQDs with circular shape determined using scanning electron microscopy, highresolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence were successfully fabricated. In addition, the impedance nyquist plot, the electron transport resistance was smallest and the incident photo to charge carrier efficiency (IPCE) was the maximum when the size of graphene quantum dots (5 nm) was used. Thus, the GQD with unique optical and structural properties can be a very attractive candidate for dye-sensitized solar cells, optoelectronics, active layer of display, and bio-imaging devices.

Efficient charge collection of photoanodes and light absorption of photosensitizers: A review

“…This category of carbonaceous materials show size‐dependent optical properties and these properties can be altered by doping with numerous metals. Kim et al used GQD layers with TiO 2 as the photoanode of DSSC in their work and hit on 6.17% PCE 108 . An improved efficiency of 11.7% was slapped by Kundu et al after refining TiO 2 photoanode with N,F,S‐codoped GQDs (NFS‐GQDs) 109 .…”

“…Kim et al used GQD layers with TiO 2 as the photoanode of DSSC in their work and hit on 6.17% PCE. 108 An improved efficiency of 11.7% was slapped by Kundu et al after refining TiO 2 photoanode with N,F,Scodoped GQDs (NFS-GQDs). 109 Each of these hetero atoms have their own role in the enhanced efficiency such as the N doping for the lowering of TiO 2 bandgap, S make the electron transport easier and F assisted strong binding with the TiO 2 surface.…”

Size Effect of Graphene Quantum Dots on Photoluminescence

“…These proprieties endow GQDs with stable fluorescence and adjustable bandgap [ 11 , 12 , 13 ]. Based on the above excellent feature, GQDs could be applied in multiple fields, such as photovoltaic devices [ 14 ], catalysis [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], solar cells [ 23 , 24 ], sensing [ 25 , 26 ], drug delivery [ 27 ], and cell imaging [ 28 , 29 , 30 , 31 ]. The hydrothermal method is a commonly used method for preparing GQDs.…”

New Assembly Method for Cellulose Derived Graphene Quantum Dots-Sensitized Solar Cells

“…GQDs have been employed in PV cells since 2010 as potential electron donors [17] and light absorbers [18]. Researchers added GQDs in all the main compartments of DSSC which are in photoelectrodes [19], light absorbers/sensitizers [18,[20][21][22][23][24][25][26][27][28][29], electrolyte [30] and counter electrode [31][32][33][34][35][36]. Most researchers have used GQDs as light absorbers co-sensitized with various dyes, such as N719, N3, and D719 in quantum dot-sensitized solar cells (QDSSCs), which are analogous to DSSCs [22][23][24][25][26].…”