Thermoelectric materials convert thermal gradients into electricity. They’re currently used in space applications to provide power, but they also have the potential to be used to increase energy efficiency by harnessing waste heat. However, to reach the point of wide-spread application, the efficiency of thermoelectric materials must be increased. This work investigates MnGeTe2, a high performing thermoelectric material. Doping/alloying was used in order to obtain a better understanding of the electronic properties by adjusting the carrier concentrations of the materials. The samples were tested for their structural and electrical properties and compared to literature. Bismuth doping was found to improve the thermoelectric figure of merit (zT) in comparison to literature values within the same composition space. Our findings also indicate that the material retains a cubic structure across a large composition space, indicating that there are opportunities for significant improvements of thermoelectric performance.