Bi2Se3 thin films were grown by metal organic chemical vapour deposition (MOCVD) on pyrex substrate in an horizontal reactor using Trimethylbismuth (TMBi) and Diethylselinium (DESe) as metal-organic sources. The effect of the growth parameters such as substrate temperature, T-g, and TMBi partial pressure, P-TMBi, on the structural, electrical and thermoelectrical properties of Bi2Se3 films, has been investigated. We noticed that a high growth temperature is very important for a good orientation of crystallites, which can be directly related to the best values of Hall mobility and Seebeck coefficient found. Therefore, a large stability of the reactions over the substrates with following growth conditions: 455degreesCless than or equal toT(g)less than or equal to485degreesC, 0.5 x 10(-4) less than or equal to P-TMBi less than or equal to 1 x 10(-4)atm and a total hydrogen flow rate D-T = 3 slm, is achieved. In these optimal growth conditions, we found a better crystalline structure of Bi2Se3 thin films using X-ray diffraction. Thus, these layers always displayed n-type conduction using Hall effect, with carrier concentration close to 2 x 10(19) cm(-3) and maximum values of Hall mobility and Seebeck coefficient of mu = 247 cm(2)/Vs and \alpha\ = 120 muV/K respectively. Then, these films appear to be very promising for thermoelectric applications. (C) 2002 Elsevier Science B.V. All rights reserved.