The Growth of CuGaTe2 Thin Films by Two‐Step Closed Space Sublimation

CuGaTe2 layers are successfully grown on Si (001) and Mo/quartz substrates using two‐step closed space sublimation (CSS). The surface morphology of the Cu2Te first layer is affected by the surface free energy of the different substrates. Cu2Te grown on Si (001) comprises hexagonal islands which are highly oriented to the (0001). Conversely, Cu2Te layers formed on Mo/quartz substrates forms a thin film. The surface morphology and the quality of the crystals in the CuGaTe2 layers are investigated. Overgrowth by CuGaTe2 of the Cu2Te islands on Si substrates is confined to the islands only and there is no nucleation on the bare substrate. On the contrary, overgrowth by CuGaTe2 on the continuous Cu2Te films on Mo/quartz substrates produces continuous thin films. Therefore, the surface morphology of the CuGaTe2 layers can be controlled by changing the substrate material because they have different surface free energies. Two‐step closed space sublimation growth of CuGaTe2 layers is achieved by introducing Cu2Te first layer. Cu2Te on Si substrate exhibits islands but is a smooth film on Mo/quartz substrates. CuGaTe2 film is obtained on the continuous film Cu2Te first layer. The surface morphology of CuGaTe2 can be controlled by changing the substrate because of different surface free energies.