The SITA Pro­ject, the bene­fi­ciary of which is i.a. Rol­tec aims to cre­ate a stable inor­gan­ic tan­dem photo­vol­ta­ic cell with increased effi­ciency and dur­ab­il­ity. Uni­ver­sit­ies, insti­tutes and rep­res­ent­at­ives of the industry par­ti­cip­ate in the pro­ject fin­anced by the European Union.

Solu­tions that increase the effi­ciency and dur­ab­il­ity of photo­vol­ta­ic cells are con­stantly being sought. Oppor­tun­it­ies for a step increase in effi­ciency and reduc­tion of the cost of pro­du­cing a kW of energy per m2 of sur­face are provided by tan­dem pan­els. The SITA con­sor­ti­um is devel­op­ing a solu­tion com­bin­ing sil­ic­on cells with CIGS cells.

Rol­tec’s tasks with­in the SITA Project:

  • indus­tri­al applic­a­tion of the back contact,
  • laser struc­tur­ing (Rol­tec the lead­er of the task),
  • mod­ule encapsulation,
  • assess­ment of indus­tri­al application.

The com­bin­a­tion of two mature tech­no­lo­gies is to res­ult in the cre­ation of a photo­vol­ta­ic cell with an effi­ciency exceed­ing 30% and a dur­ab­il­ity of over 30 years.

SITA Pro­ject in numbers:

SITA aims to explore an innov­at­ive concept of tan­dem sol­ar cells with a 2‑terminal (2T) approach based on two tech­no­lo­gies: Sil­ic­on Het­ero­junc­tion (SHJ) and Cu(In,Ga)(Se,S) 2 (CIGS) with a wide band gap. The innov­at­ive tan­dem concept — which requires no addi­tion­al cables or elec­tron­ics — is made pos­sible by the latest devel­op­ments in wide-gap CIGS, achiev­ing effi­cien­cies above 18%. SITA will demon­strate the dur­ab­il­ity of the new mod­ules in real­ist­ic out­door con­di­tions, deliv­er­ing the next gen­er­a­tion of stable inor­gan­ic tan­dem sol­ar mod­ules with the highest unit effi­ciency (>30%).

The SITA tech­no­logy will be based on SHJ mod­ules and will increase their effi­ciency by a factor of 1.5, with a mar­gin­al increase in the con­sump­tion of the most expens­ive raw mater­i­als. This, in turn, leads to a sig­ni­fic­ant reduc­tion in area-related sys­tem costs of up to 25% per installed capa­city and a cor­res­pond­ing reduc­tion in LCOE.

The effi­cien­cies of tan­dem junc­tions have recently approached or even exceeded the Shockley-Queis­s­er lim­it for single junc­tion pro­to­type devices. SITA will address remain­ing con­straints in terms of sta­bil­ity, scalab­il­ity, pro­duc­tion costs and envir­on­ment­al impact.

The SITA con­sor­ti­um, apart from Rol­tec, also includes: Upssala Uni­versitet,  Mar­tin-Luth­er Uni­versität Halle, Uni­v­er­is­ité du Lux­em­bourg, Helm­holtz-Zen­trum Ber­lin für Mater­i­ali­en und Ener­gie GmbH, imec, Centre Nation­al de la Recher­che Sci­en­ti­fique, Inter­na­tion­al Iberi­an Nan­o­tech­no­logy Labor­at­ory, Empa, Zen­trum für Sonnenen­er­gie- und Wasser­stoff-Forschung Baden-Württem­berg, Sun­plugged, Mey­er Bur­ger and Vlaamse Instelling Voor Tech­no­lo­gisch Onderzoek N.V.

You will find more inform­a­tion about the SITA con­sor­ti­um pages.

Photo from an optic­al microscope 

Tri­al cuts made with a laser using dif­fer­ent pro­cess parameters. 

SEM micro­scope photo 

It shows both the sur­face and the cross-sec­tion of the sample with laser struc­tur­ing using vari­ous pro­cess para­met­ers. Obser­va­tion made in the last stage of visu­al veri­fic­a­tion of the qual­ity of laser cuts. 

SEM micro­scope photo 

Cross-sec­tion through the laser cut observed with an SEM micro­scope. You can observe the remov­al of the CIGS lay­er from the ITO depos­ited on the glass without remov­ing the bot­tom con­tact, the inside of the laser cut and its edges. 

Fun­ded by the European Uni­on. Pro­gram: HORIZON, Call for pro­pos­als: HORIZON-CL5-2021-D3-02, Pro­ject ID: 101075626.
Hori­zon Europe is the largest research and innov­a­tion pro­gram in the his­tory of the European Uni­on. Its goal is to sup­port innov­a­tion in Europe in the field of envir­on­ment­al, energy, digit­al and geo­pol­it­ic­al chal­lenges. The pro­gram­me’s budget is EUR 95.5 bil­lion. Hori­zon Europe strengthens sci­entif­ic cooper­a­tion with­in the European Uni­on mem­ber states, increases eco­nom­ic growth and pro­motes com­pet­it­ive­ness. More inform­a­tion on the Hori­zon Pro­gram web­site.