Owing to the energy and environmental issues, energy recovery technologies attract an increasing interest. Thermoelectric power generation is a recycling technology, which directly converts heat energy into electric energy by reusing waste heat. In this study, n-type Bi₂Te2.7Se0.3 thermoelectric materials doped with Cu were fabricated by hot pressing. The Bi-Te system has excellent thermoelectric properties in the middle- and low-temperature ranges; when a certain amount of Cu dopant is added, the thermoelectric properties are improved. The thermoelectric properties of the samples doped with Cu were compared with those of the intrinsic Bi-Te-based sample without Cu doping. In addition, the effects of the Cu concentration on the thermoelectric-material structures were investigated.