The CdTe solar cell is a thin film device ( a diode) where the active part of the junction is composed of one p layer: CdTe (absorber) and one n layer: CdS (window layer).

The front contact (TCO transparent conductive oxide) must be transparent (so that the light can reach the absorber part), stable (to high processing temperatures and for long time) and conductive.

The back contact (buffer+metal) makes a chemical contact with CdTe and has to be stable.

The material used is 100 times less than for monocrystalline modules and is a negligible part of the whole cost of the module.

The fabrication process can be completely automated and the production yield of a module per minute is a possible goal.

Low cost glasses (soda lime) can be used as substrates.

Production costs of about less than 0.5 $/w have been calculated by K. Zweibel [ Progress in Photovoltaic, Vol.3, N°5, (1995) ] for thin film modules, a cost that is close to be competitive with the electric power obtained from fossil fuel.

Up to now three different thin film technologies are considered for production:

Amorphous silicon: maximum efficiency of 13% [ J. Yang ET to, Appl. Phys. Lett. 70 (1997) 2975]

CuInGaSe2/CdS: maximum efficiency of the 19,2% [ K. Ramanathan ET to. Prog. Photovolt: Res. Appl. 11 (2003) 225-230 ]

CdTe/CdS: maximum efficiency of the 16,5% [ X. Wu, Solar Energy 77 (2004) 803-814 ]

Among these the CdTe/CdS cell is the most favorite due a higher industrial scalability.