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# New Momentum in SOLVing the indium and Silver consumption issues for a sustainable Terawatt-scale Industrialization of high efficiency solar CELLS

F. Jay¹*, D. Bellet², V. Demange⁵, J.-L. Deschanvres², F. Ducroquet⁷, S. Dubois¹, T. Fix⁸, A. Fouchet⁴, C. Jimenez², D. Munoz-Rojas², A. Nominé³, J.-F. Pierson³, N. Schneider⁶, M. Treguer-Delapierre⁹

## OBJECTIVES

Support the terawatt-scale deployment of solar cells production by freeing themselves from critical material dependence

**critical materials:**
**Indium (In) and Silver (Ag)**

**Related solar cell structures:**
Single junction SHJ / TOPCon-like
2T Tandem PK/c-Si

**Targeted content:**
**No Indium
Ag <2mg/W**

**Targeted η vs ref:**
- ≤0.2%<sub>abs</sub>
- ≤0.5%<sub>abs</sub>

## SELECTED SOLAR CELL STRUCTURES

### Heterojunction

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- High efficiency >25% / high TRL

- Low temp process (<250°C)

- Double side texturized

### Topcon-like

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- High efficiency >25% / high TRL

- Med temp process (<400°C)

- Single side texturized

### Tandem 2T PK/Si

- High efficiency >35% / low TRL next generation

- Very low temp process (<130°C)

- Single/double side texturized

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liten

## ALTERNATIVE MATERIALS DEVELOPMENT

**ACCORDING SOLAR CELLS STRUCTURE SPECIFICATIONS** (material prop., surface topologies, sublayer, temperature limitation)

### n-type Transparent conductive material (TCM)

CaVO₃, and SrVO₃
→ Transfer via nanosheets

**Step 1: control of the nanosheets size**
(100nm to 500nm)

Coverage of different types of surfaces with varying degrees of roughness:

- Single-crystal size and sieving

- Putting into solution

- Deposition on solar cells

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**Step 2: Optimisation of large-area SrVO₃ and CaVO₃ deposits**

- Large-area PLD: 2-3 inches

- Magneton Sputtering: 3 inches

+ Aluminium electrodes to contact the TCO

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### p-type TCM

Cul and n-doped SnO₂
by magnetron sputtering
deposition

**Cul films** can be deposited either by sputtering of a copper iodide target or by iodination of a copper thin film (2 step process). Both kinds of films exhibit similar cubic structure.

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N:SnO₂ formed by
nitriding of a
sputtered SnO₂ film

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iCUBE

Transparent electrodes based on metallic nanowire (NW) and TCM nanocomposites

From Ag-based NW to Cu-based NW

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icmcb

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NW+metal oxide
NW+cond. polymer

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IPVF

- NW capping by **SALD** or metal co-reduction

- **Core-shell nanostructures** to improve the material stability

- Definition of **network density** following the application **TCM** or **Transparent electrode** (TE)

## Dev. supported by material/device characterization

- **Material properties:** chemical (RBS, ERDA, XRD, XPS), optical (UV-vis. Spectroscopy, SE, PL), electrical (IV, CV Hall), @ **nanometric scale:** structural (TEM, MEB, EDS, AFM), electrical (SCM, SSRM, SMIM)

- **Surface and interface properties:** electrical spectroscopy (admittance, noise), surface photovoltage, scanning Kelvin probe, APS

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## Choices supported by AI-Powered multicriteria selection

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Sustainability
Assessment

Performance
Evaluation

Multi-criteria
Decision making

Recommendation
& update

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RÉPUBLIQUE
FRANÇAISE

Liberté
Egalité
Fraternité

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PROGRAMME
DE RECHERCHE

SYSTÈMES
ÉNERGETIQUES
& ÉNERGIES
RENOUVELABLES

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**Project information:** 54months 07/2023 to 12/2027

Including funding for 9 master internships, 2 PhD thesis, 1 post-doctoral students, 4 research engineers.

This work was supported by a French government grant managed by the Agence Nationale de la Recherche under the France 2030 program, ANR-22-PETA-001

<footnote>* Corresponding author: frederic.jay@cea.fr</footnote>