Materials Science PV Enn Mellikov

Solar cell

Polycrystalline Si

Tecturing of surface

Thin film solar cell

Cu(InGa)Se 2 -based solar cells have often been touted as being among the most promising of solar cell technologies for cost-effective power generation. This is partly due to the advantages of thin films for low-cost, high-rate semiconductor deposition over large areas using layers only a few microns thick and for fabrication of monolithically interconnected modules. Perhaps more importantly, very high efficiencies have been demonstrated with Cu(InGa)Se 2 at both the cell and the module levels.

Cross section of a Cu(lnGa)Se 2 solar cell

The unit cell of the chalcopyrite lattice structure

Ternary phase diagram f the Cu-In-Se system

Pseudobinary In 2 Se 3 -Cu 2 Se phase diagram

Defect levels in CuInSe 2 Electronic levels of intrinsic defects in CuInSe 2. On the left side the theoretical values are presented and on the right side experimentally reported values are presented. The height of histogram columns on the right side represents the spread in experimental data.

Multisource elemental coevaporation camera

Relative metal fluxes and substrate temperature for different coevaporation processes stivity

Chemical bath deposition

Deposition of CdS buffer layers on Cu(InGa)Se 2 is generally made in an alkaline aqueous solution (pH> 9) of the following three constituents: 1. a cadmium salt; for example, CdS0 4, CdCl 2, CdI 2, Cd(CH 3 COO) 2 2. a complexing agent; commonly NH 3 (ammonia) 3. a sulphur precursor; commonly SC(NH 2 ) 2 (thiourea).

Choise of buffer layer materials The lattice spacing of the (112) planes of CuIn 1-x Ga x Se 2 and the (111) cubic or the (002) bexagonal planes of Cd 1-x Zn x S

Alternative buffer layers

SC parameters

Adsorbtsion of light Absorption of light with different wavelenghts in Cu(InGa)Se 2 with x=0.2

Band diagram of a ZnO/CdS/Cu(InGa)Se 2 device at 0 V in the dark

Parameters of Solar cells

Parameters of solar cells Efficiency ( ) and V oc () as a function of Cu(InGa)Se 2 band gap, varied by increasing the relative Ga content, The dashed line has slope ΔV oc / ΔE g = 1