CuInSe2/CdS thin film solar cells by r.f. sputtering

CuInSe2/CdS thin film solar cells were prepared by rf sputtering on an Al-covered glass substrate. The Al layer, deposited using an electron gun, is crystalline with an average grain size of 100μ. The Mo bottom contact, the CuInSe2 and CdS films were sputtered in sequence in the same sputtering chamber without breaking the vacuum. The CdS film deposited at substrate temperature of 200°C has a resistivity of ≈1 Ωcm due to small amount of H added during the deposition which increases the S vacancies in the film. CuInSe2/CdS sputtered solar cells have an efficiency of ≈4-5%. A higher efficiency can be obtained by improving the structural and electro-optical properties of CuInSe2 thin films.