Physical properties of electrodeposited CIGS films on crystalline silicon: Application for photovoltaic hetero-junction

P-type CIGS (CuIn_1-xGa_xSe₂) thin films are electro-deposited on a p-type c-Si substrate with a galvanostatic mode to form CIGS(p)/c-Si(p) hetero-junction. The Ga content is varied up to x = 30%. The physical properties of formed CIGS films are characterized by XRD, SEM, EDS and UV–Visible spectroscopy. With x = 30%, we obtain a single chalcopyrite phase of CIGS with a tetragonal crystal structure, a high crystallinity, an orientation toward the (112) direction and a band gap energy of 1.40 eV.AM1.5 J-V performed on the CuI_0.7G_0.3Se₂/c-Si hetero-junction reveals interesting photovoltaic parameters with an efficiency of 3.75%. In addition, using the energy diagram of the hetero-junction calculated with the Anderson model, we show that it could play a dual role when combined to a c-Si cell in a Ag–Al/c-Si(n⁺)/c-Si(p)/CIGS(p)/Al new architecture. Therefore, in addition to its interesting photovoltaic parameters, this hetero-junction can substitute the BSF.