This paper introduces a new method to selectively fabricate n-type and p-type bismuth (Bi)-telluride (Te) thermoelectric materials by the rate of addition of ethylene glycol (EG) in the Bi-Te co-electrodeposition solution. As the amount of added EG is increased, the atomic ratio of Bi in the deposited Bi-Te alloy reached a slope of 0.463 (at.% of Bi/vol.% of EG), and increased in a linear manner. When the EG content reached approximately 20% v/v, the n-type material changed into a p-type. This change implies that adjusting the EG content in the electrodeposition solution affords simple control of the Bi-Te composition. To demonstrate the applicability of the developed thermoelectric materials, thermoelectric generators (TEGs) were fabricated using electrodeposited n-type (using solution without EG) and p-type (using solution with 30% v/v EG) Bi-Te alloys. The Seebeck voltage of the pair of n-type and p-type thermoelectric materials was 140 mV and the power generated from the pair was 24.36 nW at a 10 degrees C temperature difference. (C) 2014 Elsevier B.V. All rights reserved.