Date of Award

5-3-2026

Thesis Type

PhD

Document Type

Thesis

Divisions

Institute for Advanced Studies

Institution

Universiti Malaya

Abstract

The efficiency of photovoltaic (PV) panels is crucial, as solar energy has become an alternative energy source that meets today’s global energy demands. Hence, dust accumulation and spectral mismatch have major effects on the efficiency of PV panels, around 20 %, but in extreme situations, this can reach up to 64 %. Therefore, initiatives are underway to address these issues, including PV cooling systems, conventional cleaning methods, and various coatings to enhance efficiency. In this work, a novel coating is fabricated with high transparency, excellent self-cleaning properties, and good spectral-modifying properties. Two types of powder composites are employed in this study to investigate their characteristics and energy-conversion abilities, with the aim of incorporating them into a dual-functional, spectral-modifying, and self-cleaning coating. In this work, two rare-earth-doped phosphors namely Dysprosium (Dy) doped Calcium boro-phosphor (CBP) and Europium (Eu) doped CBP were used in this work. Furthermore, calcium carbonate (CaCO3) was also used as a host for both powder compounds. Two types of powder systems were synthesized via the solid-state diffusion method, with a constant CaCO3 weight of 0.5 g and varying weight percentages (wt.%) of CBP/Dy-CaCO3 and CBP/Eu-CaCO3. The structural, morphological, and chemical compositions of the prepared CBP/Dy-CaCO3 and CBP/Eu-CaCO3 powder systems were well investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), and Fourier-transform Infrared Spectroscopy (FTIR). In addition, a photoluminescence (PL) test was conducted to assess the luminescent properties of both powder systems. It is found that the morphology, structure, and chemical composition of the CBP/Eu-CaCO3 powder system are almost similar to those of the CBP/Dy-CaCO3 powder system due to the identical usage of host material, and the same route of synthesis method was employed. However, the CBP/Eu- CaCO3 powder system showed good PL properties compared to the CBP/Dy-CaCO3 powder system by emitting three emission peaks at 591, 617, and 693 nm in the visible region. Hence, a coating system was fabricated via dip-coating method using the CBP/Eu- CaCO3 powder system incorporating polydimethylsiloxane (PDMS) as the host material, consisting of samples C1, C2, C3, C4, and C5. The morphological and structural characterizations indicated that the coating system exhibits a rough surface, and the polymer coating remains amorphous after incorporation with CBP/Eu-CaCO3. The PDMS@CBP/Eu-CaCO3 coating system also exhibited the highest optical transparency and water contact angle (WCA) of 99.18% and 105.9°, respectively. Thus, the prepared coating obtained good self-cleaning properties due to its hydrophobic surface, which repelled water and removed dust particles through rolling or sliding motion. Furthermore, the PDMS@CBP/Eu-CaCO3 coating system demonstrated its PL ability by converting a high-energy photon at 339 nm into a low-energy photon at 612 nm, assigned to the 5D0 → 7F2 transition. Based on the results, sample C4 was selected for further PV panel test due to its high wettability and luminescence properties. In addition, the coated PV panel demonstrated an improvement in efficiency of about 0.63% compared to the bare PV panel, and the overall efficiency enhancement is about 74.12%. The results obtained from this work has proven that the developed materials have performed in lab scale as well for real-time applications which shows the high potential for improving PV panel efficiency.

Initial

khm

Additional Information

Thesis (PhD) – Institute for Advanced Studies, Universiti Malaya, 2026.

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