In the last ten years, tandem solar cells based on perovskite (PK) materials have shown promising results, surpassing the theoretical limits of single junction Silicon (Si) solar cells. Even though PK/Si tandem solar cells appear capable of achieving >35% of power conversion efficiency, many challenges need to be overcome in order to upscale the PV devices from 1 cm² laboratory scale to larger areas. With that perspective, vapor deposition of the absorber layer seems promising in order to elaborate a conformal and high quality perovskite on top of textured industrial silicon wafers. In the literature, the main industrially compatible techniques to grow the PK layer can be divided into two axes: i) PK deposition by full vapor deposition techniques and ii) PK deposition by hybrid processes (mix of dry and wet processes).

In a first part, we propose pulsed laser deposition (PLD) as full vacuum scalable method to fabricate uniform black phase inorganic perovskites and charge transport layers on 707 cm² substrates (> G12 area). We first developed several PLD-grown contact layers (ITO, SnO2 and NiOx), and then demonstrated the deposition of CsPbI₂Br and CsPbI₃ on 300 mm wafers, exhibiting PL peaks at λ=648 nm (~1.91 eV) and 700 nm (~1.77 eV), with FWHM of 28.9 and 36.5 nm, respectively. The films show excellent uniformity: 0.8% in thickness and 0.2% in PL wavelength. Final device integration and performance measurements are currently underway. Looking ahead, we aim to scale-up the growth rate from the current 8 nm/min at 20 Hz to 125 nm/min using an industrial PLD system operating at 300 Hz, further highlighting PLD as a promising route for large-scale PSC manufacturing.

In a second part, we focus on a hybrid deposition process combining thermal co-evaporation, close space sublimation (CSS) and solvent step for the elaboration of organic-inorganic perovskite layer. Using different characterization techniques (X-ray Diffraction, X-Ray Photoelectron Spectroscopy, Scanning Electron Microscope, etc.), we firstly investigate the structural and chemical properties of the inorganic scaffold. The goal of this study is to understand how the homogeneity, the porosity and the composition of the first layer affect the growth of the final PK film. Simultaneously, we examine the key factors that influence the crystallization mechanism during the second wet step.

Final part will be dedicated to the stability assessment of perovskite/silicon tandem architecture under outdoor and accelerated ageing conditions.