Abstract: Conventionally, CdTe solar cells are grown in superstrate configuration where the light enters the photovoltaic device through a transparent substrate. Still, efficiencies of CdTe solar cells grown in substrate configuration have so far been considerably lower than those grown in superstrate configuration. This invention discloses a photovoltaic device (0) in substrate configuration and a process of making thereof with which efficiencies approaching those of superstrate devices can be reproducibly achieved. Furthermore, long term stability is expected to be better than in state of the art devices. This method is advantageous because the growth in substrate configuration offers several advantages like the growth on metal foils and a more precise control of the junction.