STUDY OF ULTILIZATION KAPPA-CARRAGEENAN AS CHARGE TRANSPORT TO INCREASING THE EFFICIENCY OF BULK HETEROJUNCTION HYBRID SOLAR CELL

• Main Author: Anisah
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81618
• Institution: Institut Teknologi Bandung

Developments in the renewable energy field, one of which is solar cell research, have attracted the attention of researchers in recent decades. Organic solar cells offer advantages compared to inorganic-based solar cells, namely light weight, easy to use, biocompatibility and easy integration, moreover, in the bulk heterojunction structure of organic solar cells there is a solar cell working mechanism that is more effective than solar cell device in planar configuration. In recent years, researchers have begun to combine organic-inorganic materials to form hybrid solar cell structures which are expected to further improve the performance of solar cell devices. Regarding organic materials used as active or supporting materials in solar cell device structures, biopolymers are starting to be widely developed and integrated into the structure of solar cell devices, especially for the generation of bulk heterojunction solar cells. Among biopolymers, kappacarrageenan (KC) is a type of polysaccharide that is widely used because it has potential as a conductive polymer. Kappa-carrageenan has been known to form good thin films and has high conductivity, one of which is in organic batteries, another alternative is as a doping agent in hole conductor layers (HTL) which are mixed with PEDOT (Poly (3,4-ethylenedioxythiophene)) to become PEDOT:KC. So far the research related to the addition of biopolymer into organic solar cell structure has not achieved good results. This research aims to utilize kappacarrageenan addition into the PEDOT:PSS (Poly (3,4-ethylenedioxythiophene) polystyrene sulfonate) layer in order to assist charge transport in the hole conductor layer (HTL) to improve the performance of bulk heterojunction hybrid solar cell. The experiment began with purification and preparation of the KC solution which was then mixed into a PEDOT:PSS solution with varying volume ratios. The deposition of the PEDOT:PSS:KC solution on the substrate was carried out using a spin coating technique to form a transparent thin film. Next, fabrication of hybrid bulk heterojunction solar cells with the configuration (ITO/ZnO/P3HT:PCBM/PEDOT:PSS:KC/Ag) was carried out using spin coating and vacuum evaporation techniques for the Ag electrode. Characterization was carried out to determine the morphology, optical and chemical properties of the materials used, while current density-voltage (J-V) measurements were carried out to determine the performance of the fabricated solar cell devices. From the SEM imaging results, it was found that the PEDOT:PSS thin film with the addition of KC is less homogeneous than PEDOT:PSS without KC due to the interaction between PEDOT:PSS and KC which causing KC to be trapped in the area around the PEDOT:PSS polymer chain. This result is also agree to that of XRD measurement data, where PEDOT:PSS:KC is more amorphous compared to KC itself which is known to have semi-crystalline properties. Meanwhile, the results of UV-Vis measurements of the PEDOT:PSS:KC samples show an increase in absorbance intensity for increasing KC volumes and the results of chemical characterization using FTIR show that several transmission band positions are overlap and the peak shifted for the case of PEDOT:PSS added with KC, which indicate the presence of chemical coordination between the polymer chain of PEDOT:PSS and KC. Performance measurements of solar cell devices show an increase in JSC and VOC values with the addition of KC of 6.067 mA/cm2 and 0.400 V compared to without KC of 3.213 mA/cm2 and 0.310 V. Solar cell devices with the addition of KC achieved an power conversion efficiency of 0.595%, higher than without additional KC.