High energy expectations and CO2 emissions resulting from non-renewable energy sources are the issues that require humanity to find sustainable energy solutions. Additionally, a huge amount of waste is produced in the form of heat from various industrial applications. Thermoeelectric devices are renew- able power generation systems that can convert the waste heat into electricity. State-of-the-art materials such as SiGe, Bi2Te3 and PbTe are used widely in thermoeelectric applications, however, their low energy conversion efficien- cies, high cost and toxicity limit the usability of these materials for long-term power generation. Halide perovskites offer economical (low-energy and less expensive) and non-toxic synthetic methods and operational environment. Despite these opportunities, their low efficiencies caused by ultralow electri- cal conductivities suppress the usability of these materials for commercial applications. Decreasing the dimensionality of these materials and doping them, provides potential improvement in their thermoeelectric properties. This thesis gives the theoretical understanding of thermoelectrics and their applications. Along with that, the novel studies on thermoeelectric properties of low dimensional halide perovskite derivatives and the doping effects on these materials will be presented. Mainly, the synthesis and char- acterization of zero-dimensional (0D) Cs3Cu2I5 perovskite derivatives that are substitutionally doped with barium (Ba) and molecularly doped with Magic Blue (MB) will be introduced and their effects for the improvement of thermoeelectric properties will be discussed. Additionally, copper (Cu) based mixed metal-halide (CuI1−xBrx) thin film and crystal synthetic meth- ods will be presented as an alternative route to metal halide thermoeelectric materials with improved electrical conductivities
