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Technical Info

The facility is involved in

Manufacturing of silicon solar cells
Manufacturing of multijunction solar cells based on III-V Semiconductors
Manufacturing of advanced solar cells: intermediate band solar cells, thermophotovoltaic solar cells, etc.
Material and process characterization: crystallographic analysis of thin single-crystal film III-V materials, concentration of impurities, lifetime, spectroscopy, sheet resistance and resistivity, wavelength resolved light absorption or emission,…
Device characterization: solar simulators, I-V curve measurement, spectral responsivity, photoluminescence and electroluminescence spectroscopy,…
Modeling of solar cells: 3D distributed model code for SPICE Software, and TCAD physics-based numerical modeling.
Reliability and accelerated test of III-V solar cells: temperature accelerated life test

MAIN TECHNICAL FEATURES:

1.-Manufacturing of silicon solar cells

Dicing saw for wafers and glass substrates, model DISCO DAD321 for round (6”) and square wafers (156x156mm). Cut resolution of 1µm and a maximum stroke length of 32mm.
Wet benches. Etching, texturing and cleaning available for 2” and 4” wafers.
Diffusion furnaces. 6 furnaces for doping (P and B), oxidation and annealing wafers up to 4”.
PECVD reactor. Plasma enhanced chemical vapor deposition of silicon nitride coatings. Up to 4” wafers.
Photolithography mask aligner for 2’’ wafers
Physical Vapor Deposition Equipment. E-gun and Joule-effect evaporation. Ti, Pd, Ag, Al. Up to to 4” wafers

2.- Manufacturing of multijunction and advanced solar cells

Cleaning and etching wet benches: acids, organics, plasma asher, contact layer etching, mesa etching
Photolithography Mask aligner - SUSS MicroTec MJB4. High-resolution photolithography in substrates and wafers up to 4''/ 100mm.
Wirebonder DELVOTEK 5430. Equipment to make aluminum/gold wire connections with 17.5 to 75 um diameter.
Electron Beam Physical Vapor Deposition Tool- Classic 500 Twin High Vacuum Coating System. Separate chambers for metal and dielectric coatings
Joule effect Physical Vapor Deposition Tool for metals- Telstar Vacudel 300
Joule effect Physical Vapor Deposition tool for dielectrics
Rapid Thermal Process (RTP). Wafers up to 6’’; maximum heat slope of 75 K/s and temperatures up to 1000 °C; Anneal atmospheres available: Nitrogen, Hydrogen and Forming.
Plasma asher. Low pressure plasma system from DIENER ELCTRONIC to clean semiconductor wafers.
Sputtering system to produce thin films. PVD-MT/2M3T equipped with two sputtering RF magnetrons and three resistive thermal evaporation sources in the same process chamber.

3.- Material and process characterization

Inductively Coupled Photoconductance Decay lifetime tester. Sinton’s WTC-120 model. Measure of lifetime of minority carriers in p-type and n–type wafers. Sample sizes from 2” to 8”.
Microwafe Photoconductance Decay lifetime tester. Semilab WT-2000, mapping lifetime on silicon wafers up to 8”. Also performs LBIC (Laser Beam Induced Current) measurements.
Spectroscopic ellipsometer. HORIBA IBON JOVIN. Characterization of thin films in the 190-850nm wavelength range with 2nm resolution.
Four point probe. Sheet resistance and resistivity of a wide range of materials.
FTIR. Fourier Transform Infrared Spectrometer to measure the absorption or emission of light at different wavelengths.
High Resolution X-Ray Diffractometer. 5 arc sec Ge(440) point focus module (Bartels monochromator); 19 arc sec hybrid (combination x-ray mirror + channel cut Ge(220) monochromator) line focus module; Triple axis module with triple axis detector and rocking curve detector.

4.- Device characterization

Solar Simulator ORIEL SOL2A. 1000W Xe lamp. Sample Size: Max 6 x 6".Quantum Efficiency measurements. IQE-AC-XEN-EXT1. Spectral Range: 300 - 1800nm. Sample Size: Max 6 x 6".
I-V curve measurement system of single and multijunction solar cells under standard test conditions
Spectral responsivity (SR) measurement system, from 300 to 1840 nm and cell sizes from 1 mm2 to 1 cm2. It is totally adapted to measure multijunction solar cells by using a combination of different LED and laser diode light sources (530 nm, 740 nm, 940 nm and 1300 nm).
Photoluminescence and Electroluminescence Spectroscopy of III-V or other luminescent materials.
Electroluminescence Intensity Mapping. In house developed system to measure the spatial uniformity of the light emission of a solar cell. Light emission of the cell is captured by a CCD camera and selective filters to visualize each subcell.

5.- Modeling of solar cells

3D Distributed Model: in house developed code for SPICE Software
TCAD: 2D and 3D Silvaco Software adapted for III-V single and multijunction solar cells.

6.- Reliability and accelerated test of III-V solar cells

Climatic Chamber Thermotron SM-8-8200. Temperature range from -70ºC to +180ºC (-94ºF a +356ºF) and humidity control and forced convection
Forced convection electric oven for temperature accelerated life test. Temperature control between +5ºC and 250ºC.
On sun cell degradation. Homemade equipment able to measure light I-V curves of up to 96 cells in a module installed in our solar tracker.

LIMITATIONS OR CONSTRAINTS :

The access will be allowed with technical and scientific assistance from staff of the Instituto de Energía Solar (UPM)

TYPICAL SERVICES OR RESULTS

Research on new solar cell structures
Fabrication of silicon solar cells
Specialties in silicon technology: n-type substrates, Boron emitters, very thin wafers, bifacial structures
Processing of semiconductors for companies and other research centers
Developing of suitable processing methods for third generation solar cells
Research on defect engineering approaches for unconventional silicon wafers.
Characterization of impurities and defects in crystalline silicon wafers and cells.
Material and device characterization of multijunction and advanced solar cells.

LIST OF SERVICES AGAINST PAYMENT

Services are done with the reference prices:

Participation to Research Projects: