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Item Energy from salt gradient solar pond(UMT, Lahore, 2016) Muhammad Afzal DogarPakistan is deficient in power supply according to demand. However, there is an abundant source of energy available in this country. Solar energy is available almost throughout the year everywhere in Pakistan. The question is how to harness it within Pakistan, sustain and use it. Salt gradient solar pond (SGSP) is one of the viable sources to harness solar energy and store it as well. The materials for this technology are abundantly available in Pakistan. As a backyard experiment, a small and simple salt gradient solar pond (SGSP) is constructed. The cost analysis for making Salt Gradient Solar Pond (SGSP) in Pakistan is practically performed. This is something which may solve the energy problems in Pakistan, somewhat partially if not entirely. The use of SGSP is also a promising process to reduce the environmental pollution in Pakistan.Item A density function theory study of the electronic and optical properties of cesium lead halide perovskites for potential application in solar cell(UMT, Lahore, 2016) Muhammad WaqasThe current study was planned to use WIEN2k code in order to calculate the structural, electronic and optical, properties of the lead halide perovskites CsPbX3 (X = Cl, Br, I). Lead halide perovskites had attracted enormous attention as optoelectronic materials, because these materials have power conversion efficiency up to 20 %. So as to calculate the optical, structural, and electronic properties of cubic perovskites CsPbX3 (X = Cl, Br, I), full potential linear augmented plane wave (FP-LAPW) method was opted, that was based on density functional theory (DFT) within LDA, GGA-PBE and mBJ approximation. We have found a good agreement between experimentally measured values and theoretically calculated lattice constants. The perovskite compound CsPbX3 (X = Cl, Br, I) has direct and wide band gap located at point of R-symmetry, while the band gap decreased from ‘Cl’ to ‘I’ down the group,. The study of the densities of electrons has revealed strong covalent bonding between Pb and halides, while strong ionic bonding between Cs and halides. The reflectivity, refractive indices, absorption coefficients, real and imaginary parts of dielectric function, optical conductivities, and the other optical properties were calculated. Modeling of these perovskites compounds have direct band gap nature and high absorption power in visible-ultraviolet range that enabled to study the potential applications of these compounds in solar cell application.