Development of titanium dioxide based compact layers and light scattering layers for enhanced dye-sensitized solar cell
Dye-sensitized solar cells (DSSCs) are the third-generation solar cell that capable of converting solar energy into electrical energy. Titanium dioxide (TiO2) as a photoanode has faced a lot of drawbacks such as low dye loading capacity, a small range of light scattering, high recombination effec...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2020
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/92717/1/FS%202020%2045%20-%20IR.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Dye-sensitized solar cells (DSSCs) are the third-generation solar cell that
capable of converting solar energy into electrical energy. Titanium dioxide (TiO2)
as a photoanode has faced a lot of drawbacks such as low dye loading capacity,
a small range of light scattering, high recombination effect and low charge
transport ability that subsequently reduces its power conversion efficiency
(PCE). In this work, the enhancement of DSSC performance was studied by the
modification of photoanode, specifically on the fabrication of a new compact layer
(CL) and light scattering layers (LSLs). A dense, compact and homogenous TiO2
CL was optimized and prepared using response surface methodology by central
composite design (RSM/CCD) and heat treatment assisted electrospinning,
respectively. The TiO2 CL was successfully optimized with less than 5% residual
standard error (RSE) and capable of enhancing the PCE up to 76.88% compared
with the bare photoanode (1.73%). This is due to an improved electron lifetime
(τn) and charge collection efficiency (ηc), resulting in a low recombination effect
that leads to a higher PCE. Two LSLs were prepared in this study, namely
polyvinyl alcohol (PVA/TiO2) nanofibers and TiO2 decorated by graphene
quantum dot (TiO2-GQD). The PVA/TiO2 was prepared using electrospinning
while TiO2-GQD was prepared via electrodeposition and drop-casting technique.
Both PVA/TiO2 nanofibers and TiO2-GQD LSLs were successfully optimized
using RSM/CCD with less than 5% RSE. Upon the addition of TiO2-GQD LSL
onto the photoanode, the PCE increased up to 5.01% compared to the
photoanode with PVA/TiO2 nanofibers LSL (4.06%) and bare photoanode
(3.06%). This increment is due to the longer τn, higher ηc, higher dye loading
capacity and higher light reflectance, demonstrating a good light scattering
material. Furthermore, a fully flexible photoanode with TiO2-GQD LSL has
successfully fabricated on indium doped tin oxide/polyethylene naphthalate
(ITO/PEN) flexible substrate via electrodeposition and drop-casting technique.
The fully flexible DSSC device consisting of photoanode with TiO2-GQD LSL showed an enhanced PCE of 5.18% compared to the bare photoanode (2.65%).
The vast enhancement of PCE was due to the increase in the dye loading
capacity (more dye can be adsorbed) and light scattering ability (more light can
be scattered) upon the addition of TiO2-GQD LSL. In a nutshell, the introduction
of CL and LSLs has successfully increased the DSSC performance. |
|---|