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In this paper, heat transfer characteristics of nickel coating over aluminium and mild steel are examined using jet impingement cooling. A rectangular sheet of dimension 10 cm × 3.5 cm × 0.1 cm taken as the test piece is coated with 4 g nickel acetate tetrahydrate precursor in the chemical vapor deposition (CVD) process for 85 mins. Heat transfer characteristics are studied on three layers of nickel coating (no coating, first coating, and second coating) with an impinging air-jet velocity of 3.5 ms−1 and 6 ms−1. The effect of Reynolds number, the thickness of the coating, jet velocity, distance from the stagnation point, and nozzle diameter on the heat transfer coefficient are investigated. The results show an increase in convective heat transfer characteristics with the Reynolds number, the thickness of the coating, and the nozzle diameter and a substantial decrease with deviation from the stagnation point.

Quantum Dots (QDs) are proficient in increasing the efficiency of solar cells due to their property of multiple exciton generation (electron-hole pairs) after the collision with a single photon of energy exceeding the size of the bandgap. These nanostructures can be synthesized by the bottom-up approach in which Chemical Vapor Deposition (CVD) technology offers great benefits of high throwing power and provides a cost-effective solution for large scale fabrication. The different types of CVD methods used in the fabrication process are discussed here for example - Plasma chemical vapor deposition (PCVD) is a technique in which various precursors can be used; reactive organic and inorganic materials undergo disintegration and radical polymerization while being exposed to a high-energy plasma stream for depositing a thin film over the surface of the substrate at a relatively lower temperature. In Metal-organic chemical vapor deposition (MOCVD) volatile organo-metallic precursors are deposited on the surface of the substrate under vacuum. Hot-wire chemical vapor deposition process (HWCVD) is a technique that involves the thermal deposition of precursor gases on the substrate. Some of the recent researches highlighting the fabrication of Quantum Dot Solar Cells (QDSC) and enhancing their properties for achieving high solar energy conversion efficiency using CVD methods have been discussed. Surface properties of these deposited films by CVD have been analyzed using several techniques which are discussed here. At last, challenges faced in the fabrication of QDSC are discussed and the areas of improvement and future outlook of solar cells are suggested.