The main objective of this thesis work is to synthesis quantum-confined structures, tailor their properties and investigate their applicability to photovoltaics. In this context, quantum-confined silicon nanocrystals (SiNes) are synthesized and surface engineered to tailor and understand their properties. Also a synthesis method for copper (Cu) oxide nanomaterials is developed with control over band energy diagram and optical properties. Finally these engineered quantum-confined nanostructures are successfully implemented in all-inorganic third generation photovoltaic devices with various device architectures. One of the important finding of this work is the dopant-dependant surface chemistry of doped SiNes and found that their optoelectronic properties and Fermi level are influenced by the different surface chemistries of the SiNCs. Secondly, the functionality of tailored SiNCs and Cu-oxide nanomaterials is demonstrated by fabricating all-inorganic solar cells. Some of these devices result in the highest open circuit voltage all-inorganic solar cells devices based on SiNCs. Devices that utilize SiNCs and CuO NPs were therefore presented for the first time in all-inorganic third generation architectures, which also made used of highly novel atmospheric pressure plasma processes.