Traditionally only symmetrical leg configurations were employed to evaluate the performance of the thermoelectric generator. With modern manufacturing technology, the complex shape of a thermoelectric leg can be made cost effectively. The current study proposes a novel design of a thermoelectric generator with asymmetric and segmented leg configurations with materials of modified lead telluride (material-1) and modified bismuth telluride (material-2). The p-type leg of traditional flat plate geometry and n-type leg of exponential variation area with geometric parameter 'a' is considered. The effect of efficiency, work output, work ratio and output current on the geometric parameter with temperature ratios and load ratios of the designed thermoelectric generator were investigated. Theoretical results revealed that the geometric parameter has a strong influence on the temperature ratio and load ratio. Also, lower temperature ratio has the enhanced thermal performance within the Carnot cycle efficiency for the designed segmented thermoelectric generator. Nearly, 33.3% and 5% increase in output current and overall efficiency of the segmented thermoelectric generator is observed with a temperature ratio range within 0.45-0.55. Dimensionless work ratio compared the efficiency of a proposed segmented thermoelectric generator with a non-segmented device, which revealed that for effective segmentation, appropriate materials and geometry should be carefully matched. Thus, the present modified thermoelectric generator provides higher output power than those designs, which incorporate a single pin material for efficient energy conversion. (C) 2019 Elsevier Ltd. All rights reserved.