Epitaxy, Si-Foils and SiC Deposition

R&D Services

Our R&D services comprise:

c-Si Thin-Film on Foreign Substrates

CVD and Epitaxy

Kerff-Less Wafering

One specialist field within crystalline silicon solar cells is that of crystalline Si thin-film solar cells (CSiTF solar cells). Here, the desirable qualities of wafer and thin-film solar cells are combined: high efficiency without degradation and low levels of silicon consumption.

The manufacturing concepts we are employing at Fraunhofer ISE use epitaxy or recrystallization to produce the silicon layers in CSiTF cells. These layers are either fabricated directly on inexpensive substrates (e.g. low-grade silicon wafers or ceramics), or are attached to suitable substrates using transfer technology after their production. The substrate-layer stacks thus created are called wafer equivalents. Customized functional coatings, such as those made from silicon carbide, are being developed for different wafer equivalents. Furthermore, cell and module concepts that are tailored to these wafer equivalents are also the subject of our research and development work; for example module-scale, integrated cell connection or nanotextures.

These research topics all involve testing for basic operating functions and development that promotes high throughput and low manufacturing costs.

In addition, we not only develop technology for CSiTF solar cell and module concepts, but also generate expert knowledge and file patents that are available for licensing.

We also offer the following services:

  • Encapsulation and infiltration with µc-Si/µc-SiC
  • Si epitaxy (n-, p-doped)
  • Porous silicon formation, reorganization and lift-off
  • Amorphous SiC deposition
  • Annealing (H2, Ar, N2 atmospheres)
  • Crystallization (solid phase and liquid phase zone melting)
  • Dopant profile characterisation by Spreading Resistance Profiling  (SRP) and Electrochemical Capacitance-Voltage (ECV) measurements
  • X-Ray diffraction (XRD;Glacing-Incidence-XRD, rocking curve and X-ray reflectometry)
  • Laser marking of wafered ingots
  • Laser cutting of silicon in a variety of shapes and formats
  • Grinding/polishing of cross-sections and beveled sections for sample characterisation and other purposes
  • Cleaning/diffusion/oxidization of materials with diverse impurity classifications and greatly varying dimensions, performed in systems divided into cleanliness classes
  • Plasma texturing
  • Remote plasma hydrogen passivation (RPHP) – passivating Si bulk defects by in-diffusion of atomic hydrogen

Selected Research Projects



Development of Nano-Porous Silicon Layers in an Inline Process



High-Efficiency III-V Multi-Junction Solar Cells on Silicon



Nanoimprint Lithography for Extremely Fine Solar Cell Structures


Current publications of the research topic Epitaxy, Si-Foils and SiC Deposition: