STUDY ON THE PUSH COATING FOR A LARGER MODULE OF ACTIVE LAYER FILMS

• Main Author: NG, JI WEI
• Format: Final Year Project Report
• Language: English; English
• Published: Universiti Malaysia Sarawak, (UNIMAS) 2020
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://ir.unimas.my/id/eprint/36724/1/STUDY%20ON%20THE%20PUSH%20COATING%20FOR%20A%20LARGER%20MODULE%2024pgs.pdf; http://ir.unimas.my/id/eprint/36724/2/STUDY%20ON%20THE%20PUSH%20COATING%20FOR%20A%20LARGER%20MODULE%20ft.pdf; http://ir.unimas.my/id/eprint/36724/
• Institution: Universiti Malaysia Sarawak

A solar cell is used to convert solar energy into electricity by the photovoltaic effect. There are multiple different functional layers in a solar cell and the active layer is the core of a solar cell as the photovoltaic effect takes place over there. Spin coating is the conventional method to deposits the thin film of active layer by the centrifugal force, however, spin coating discards a large amount of hazardous solvent wastage during the process, it is highly expensive in terms of materials and it only able to fabricate a small and limited coverage area. Therefore, to resolve these problems, push coating is introduced, another method that deposits the thin film by the capillary force. In this project, both spin and push coating methods are performed to study the film condition produced. Besides, the Polydimethylsiloxane (PDMS) stamp condition throughout the push coating is studied in this project as well. In this project, the spin coating is performed under different condition including the stamping duration and additional weight on the PDMS stamp while the spin coating is performed as a reference of the film condition to compare with push coating. Throughout the push coating, the film condition obtained is different from every trial and the PDMS stamp is swollen after the stamping process. In the push coating, the PDMS stamp’s mass increased due to the solvent retention; the PDMS stamp bent as well due to the solvent sorption and desorption kinetics. The adsorbed solvent in the swollen stamp can be removed by annealing the stamp. The push coating is performed at a larger substrate (5 × 5 cm2), the film condition is improved after applied additional weight on top of the PDMS stamp and by increasing the stamping duration. In the spin coating, the film condition is smoother than all the films produced by the push coating method. In conclusion, in this project, the push coating can perform at a larger substrate (5 × 5 cm2), which is much larger than all the previous research (2.5 × 2.5 cm2). Unfortunately, further investigation is required to obtain the optimum results for the film’s thickness and condition.