Solar Cell Analysis and Qualification

The increase in performance of industrially produced solar cells has now resulted in levels of conversion efficiency which only a few years ago were considered unattainable. This huge achievement has been made possible by closely coordinating the analysis of performance-limiting factors with the development of technological improvements which are specifically raising the performance limitation bar ever higher. Thanks to our many years of experience in solar cell physics and the use and continuous development of the latest measurement and evaluation methods, we at Fraunhofer ISE have been able to make a major contribution to this development.
We can offer you our wide-ranging experience in the analysis of solar cells, not only for the further improvement of your existing technology but also in particular to assist you with the development of new process steps. At PV-TEC, we can carry out diverse investigations for solar cell analysis on your behalf, ranging from detailed individual analyses, including referral back to the starting material and solar cell precursors, to the examination of large piece quantities. Your personal contact will draw up a list of the various services to match your requirements and will coordinate processing and reporting the results.

At our CalLab PV Cells, a calibration laboratory accredited for solar cells to ISO17025, we can also measure the current-voltage characteristic curve and the spectral response of most types of solar cells with high precision and in a manner traceable to SI units.

Methods and Equipment

The following equipment in particular is available for solar cell analysis and for the background analysis of starting material and precursors:

  • IV characteristic curves with illumination and in the dark
  • Evaluation for overall series and parallel resistance, dark currents, ideality factors
  • Local and large-area quantum efficiency measurement (EQE)
  • Spectral reflectance and local internal quantum yield (IQE)
  • SunsVoc characteristic curve measurement
  • Current topography (LBIC) and diffusion length topographies (SR-LBIC)
  • SEM analysis: Recombination activity (EBIC), crystal orientation and grain boundary classification (EBSD), chemical composition (EDX), luminescence (CL)
  • Photoluminescence imaging (PL on wafer)
    • Dislocation density topographies on as-cut wafer
    • Lifetime topographies
    • Iron and chromium distribution topography
  • Fourier spectroscopy: oxygen/carbon analysis
  • Hall measurements
  • Chemical analysis for metals and dopants (ICP-OES, AAS)
  • Lifetime measurement (QSSPC)
  • Lifetime topographies (MWPCD, CDI, PL)
  • Layer resistance topographies (4 point, SRI)
  • Doping profiles (Stripping Hall)
  • Ellipsometry (single wavelength, spectral)
  • Microscopy
  • 3D profilometry (confocal microscopy, laser profilometry)
  • Photoluminescence/electroluminescence imaging (PL/EL on solar cell)
    • Series resistance topographies
    • Dark current topographies
    • Emitter layer resistance topographies
    • Microcrack analysis
  • Thermal imaging (ILIT, DLIT): Shunt analysis, breakdown behavior
  • Contact resistance topography
  • Metallization resistance measurement (TLM)
  • Simulation of temperature processes with Sentaurus

We can also investigate large piece quantities with our inline measurement equipment:

  • Wafer input inspection
    • Geometry inspection (B&W vision)
    • Chipping inspection (B&W vision)
    • Wafer thickness and thickness topography
    • Analysis for microcracks and precipitates (IR transmitted light)
  • Base and emitter layer resistance (inductive layer resistance measurement)
  • Lifetime measurement (QSSPC)
  • Texture inspection
  • Layer thickness and layer uniformity inspection (color vision)
  • Solar cell output inspection
    • IV characteristic curve measurement (light, dark, SunsVoc)
    • Metallization resistances
    • Color inspection
    • Printed image inspection