Experimental setup for camera-based measurements of electrically and optically stimulated luminescence of silicon solar cells and wafers

Hinken, David; Schinke, Carsten; Herlufsen, Sandra; Schmidt, Arne; Bothe, Karsten; Brendel, Rolf

doi:10.1063/1.3541766

Cited by 45 publications

(20 citation statements)

References 31 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electronic gain of the camera is measured to be close to one, meaning one photon absorption results in one digital count, thus utilising the weak luminescence from the unpassivated brick surface well, if absorbed. This is in good agreement with gain factors given in Hinken et al 34 The chip is backilluminated, deep-depleted and utilises a near infrared (NIR) anti reflection coating for enhanced silicon luminescence absorption. Precise thermoelectric cooling keeps a constant CCD operation temperature of 243 6 0.05 K for all measurements shown in this work.…”

Section: Optical Distortions and Image Deconvolutionsupporting

confidence: 88%

On the method of photoluminescence spectral intensity ratio imaging of silicon bricks: Advances and limitations

Mitchell

Weber²,

Walter

et al. 2012

Journal of Applied Physics

View full text Add to dashboard Cite

Spectral photoluminescence imaging is able to provide quantitative bulk lifetime and doping images if applied on silicon bricks or thick silicon wafers. A comprehensive study of this new method addresses previously reported artefacts in low lifetime regions and provides a more complete understanding of the technique. Spectrally resolved photoluminescence measurements show that luminescence originating from sub band gap defects does not cause those artefacts. Rather, we find that optical light spreading within the silicon CCD is responsible for most of the distortion in image contrast and introduce a method to measure and remove this spreading via image deconvolution. Alternatively, image blur can be reduced systematically by using an InGaAs camera. Results of modelling this alternative camera type and experiments are shown and discussed in comparison. In addition to eliminating the blur effects, we find a superior accuracy for lifetimes above 100 ls with significantly shorter, but dark noise limited exposure times. V

show abstract

Section: Optical Distortions and Image Deconvolutionsupporting

confidence: 88%

On the method of photoluminescence spectral intensity ratio imaging of silicon bricks: Advances and limitations

Mitchell

Weber²,

Walter

et al. 2012

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…1. For a more detailed description of the setup, see [11]. According to [4], the PL signal is related to the excess carrier density Δn, which is determined from calibrated conductivity measurements carried out in the same setup for a specific sample area.…”

Section: Measurement Principlementioning

confidence: 99%

Reverse Saturation Current Density Imaging of Highly Doped Regions in Silicon Employing Photoluminescence Measurements

Müller

Bothe

Herlufsen

et al. 2012

IEEE J. Photovoltaics

View full text Add to dashboard Cite

We present a camera-based technique for the local determination of reverse saturation current densities J 0 of highly doped regions in silicon wafers utilizing photoconductancecalibrated photoluminescence (PL) imaging at different illumination intensities. We apply this approach to 12.5 × 12.5 cm 2 float zone silicon (Si) samples with textured surfaces and a homogeneous phosphorous diffusion with sheet resistances between 24 and 230 Ω/ . We find enhanced PL emission at metallized regions of a sample due to reflection of long-wavelength light at the sample rear. In order to allow for a transfer of the calibration function relating the camera PL signal to the excess charge carrier density Δn, our measurement setup comprises an optical short-pass filter in front of the camera that effectively blocks wavelengths above 970 nm. Investigating samples comprising local metal contacts to the highly doped regions prepared by screen printing of silver paste, we find a significantly higher J 0 ,m eta llized = 1000 fA/cm 2 for the metalized areas compared with the nonmetallized area characterized by J 0 ,n o n m eta llized = 330 fA/cm 2 .

show abstract

“…The case of an infinite contact resistance occurs when the contact opening of, for example, SiN x by etching or laser ablation was locally unsuccessful. The experimental luminescence imaging set-up, similar to the one described in [29], uses a 790 nm laser for optical excitation, a fourquadrant power supply for electrical excitation and a silicon charge-coupled device camera for luminescence detection. The I-V measurements including the Suns-V OC measurements were carried out within the same set-up.…”

Section: Experimental Results: Luminescence Signature and R S Loc Imagesmentioning

confidence: 99%

Contact fault characterisation of complex silicon solar cells: a guideline based on current voltage characteristics and luminescence imaging

Padilla

Reichel

Hagedorn

et al. 2015

Progress in Photovoltaics

View full text Add to dashboard Cite

Highest efficiency solar cells in industrial and R&D environments are increasingly sensitive to local performance limiting processing faults, which are best characterised by spatially resolved characterisation techniques. This work contains a discussion on the processing faults related to contact resistance and finger interruptions in interdigitated back contact silicon solar cells, which are prime example for a complex cell structure. Using experimental and simulated current-voltage measurements and luminescence images, we explore the strongly non-linear effect of poor local contact resistances on the global series resistance, fill factor, short circuit current density and efficiency. A good agreement between global and spatially resolved characterisation of faults is found, and potential artefacts are discussed. In conclusion, we present seven cases of contacting faults in interdigitated back contact cells with distinct characteristics that can be identified using a flow chart of experiments. The resulting guideline should assist silicon solar cell manufacturers in localising and quantifying local contacting faults that reduce the cells efficiency in manufacturing of complex solar cells.

show abstract

Experimental setup for camera-based measurements of electrically and optically stimulated luminescence of silicon solar cells and wafers

Cited by 45 publications

References 31 publications

On the method of photoluminescence spectral intensity ratio imaging of silicon bricks: Advances and limitations

On the method of photoluminescence spectral intensity ratio imaging of silicon bricks: Advances and limitations

Reverse Saturation Current Density Imaging of Highly Doped Regions in Silicon Employing Photoluminescence Measurements

Contact fault characterisation of complex silicon solar cells: a guideline based on current voltage characteristics and luminescence imaging

Contact Info

Product

Resources

About