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1

Imaging methods of detecting defects in photovoltaic solar cells and modules: a survey

Maziuk Maurycy, Jasińska Laura, Domaradzki Jarosław, Chodasewicz Paweł

Metrology and Measurement Systems

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2023

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Vol. 30, nr 3

381--401

EN

In pursuit of increased efficiency and longer operating times of photovoltaic systems, one may encounter numerous difficulties in the form of defects that occur in both individual solar cells and whole modules. The causes of the occurrence range from structural defects to damage during assembly or, finally, wear and tear of the material due to operation. This article provides an overview of modern imaging methods used to detect various types of defects found in photovoltaic cells and panels. The first part reviews typical defects. The second part of the paper reviews imaging methods with examples of the authors’ own test results. The article concludes with recommendations and tables that provide a kind of comprehensive guide to the methods described, depending on the type of defects detected, the range of applicability, etc. The authors also shared their speculations on current trends and the possible path for further development and research in the field of solar cell defect analysis using imaging.

2

Organiczne diody elektroluminescencyjne na bazie pochodnych pirazolochinoksalin

Pokladko-Kowar Monika, Wojtasik Katarzyna

Przegląd Elektrotechniczny

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2022

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R. 98, nr 9

220--223

PL

Pochodne pirazolochinoksalin (A-PQX) badano pod kątem zastosowań w organicznych diodach elektroluminescencyjnych (OLED). Wykonane zostały pomiary widm absorpcyjnych, fotoluminescencyjnych oraz elektroluminescencyjnych. Zbudowane zostały jednowarstwowe komórki o strukturze ITO/PEDOT:PSS/PVK+A-PQX/Ca/Al. Wyznaczone zostały parametry charakterystyczne dla OLED. Maksymalna luminescencja otrzymana dla tych struktur wynosiła 884 cd/m2 dla diody na bazie 7-N,N-dietylo-1-fenylo-3-metylo-1H-pirazolo[3,4-b]chinoksaliny (7- PQX).

EN

Pyrazoloquinoxaline derivatives (A-PQX) have been studied for applications in organic light emitting diodes (OLEDs). Single-layer OLEDs with the structure: ITO/PEDOT:PSS/PVK+A-PQX/Ca/Al were built. Parameters characteristic for OLED were determined. The absorption, photoluminescent and electroluminescent spectra were measured. The maximum luminescence obtained for these structures was 884 cd/m2 for a diode based on 7-N,N-diethyl-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline (7A-PQX).

3

Optimization of technology of diode laser mirror processing to maximize the threshold of catastrophic optical degradation

Dąbrowska Elżbieta, Teodorczyk Marian, Szymański Michał, Maląg Andrzej

Optica Applicata

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2020

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Vol. 50, nr 4

593--607

EN

In this paper, optimization works on the technology of passivation and optical coatings of laser diode facets are described. The main goal is to increase the optical power at which the catastrophic optical mirror damage occurs. The coatings and passivation processes have been done in an ion source-aided electron-beam evaporator. The essence of passivation was to remove native oxides and produce a native thin nitride layer with simultaneous saturation of the dangling atomic bonds. The procedure has been realized with the help of nitrogen or forming gas (N2 + H2) beam. As a result, we present sets of technological parameters allowing to increase the catastrophic optical mirror damage threshold of diode lasers.

4

Noise and optical spectroscopy of single junction silicon solar cell

Skvarenina L., Macku R.

Metrology and Measurement Systems

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2018

|

Vol. 25, nr 2

303--316

EN

Noise spectroscopy as a highly sensitive method for non-destructive diagnostics of semiconductor devices was applied to solar cells based on crystalline silicon with a view to evaluating the quality and reliability of this solar cell type. The experimental approach was used in a reverse-biased condition where the internal structure of solar cells, as well as pn-junction itself, was electrically stressed and overloaded by a strong electric field. This gave rise to a strong generation of a current noise accompanied by local thermal instabilities, especially in the defect sites. It turned out that local temperature changes could be correlated with generation of flicker noise in a wide frequency range. Furthermore, an electrical breakdown in a non-stable form also occurred in some specific local regions what created micro-plasma noise with a two-level current fluctuation in the form of a Lorentzian-like noise spectrum. The noise research was carried out on both of these phenomena in combination with the spectrally-filtered electroluminescence mapping in the visible/near-infrared spectrum range and the dark lock-in infrared thermography in the far-infrared range. Then the physical origin of the light emission from particular defects was searched by a scanning electron microscope and additionally there was performed an experimental elimination of one specific defect by the focused ion beam milling.

5

Metody identyfikacji uszkodzeń modułów fotowoltaicznych – badanie przypadku

Mik K., Bugaj M., Klein M.

Instal

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2018

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nr 11

12--15

PL

W pracy przedstawiono metody identyfikacji uszkodzeń modułów fotowoltaicznych, takie jak: inspekcja wizualna, wyznaczenie charakterystyki prądowo-napięciowej, termowizja i elektroluminescencja. Opisane metody pozwalają na kompleksową analizę stanu technicznego modułu fotowoltaicznego, co zaprezentowano na przykładzie porównania dwóch modułów z tej samej serii, nowego i po trzech latach eksploatacji.

EN

In this paper methods used to identify photovoltaic module failures: visual inspection, measurement of current-voltage characteristic, thermography and electroluminescence have been presented. The described methods allow to provide a comprehensive analysis of photovoltaic module condition. Their practice use has been demonstrated by comparison of two modules from the same batch, a new one and the other one after 3 years of exploitation.

6

Projektowanie układów optycznych do elektroluminescencyjnych źródeł światła z wykorzystaniem metody graficznej

Zalewski S.

Prace Naukowe Politechniki Warszawskiej. Elektryka

|

2016

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z. 147

3--100

PL

Praca opisuje proces projektowania układów optycznych stosowanych w oprawach oświetleniowych wykorzystujących diody elektroluminescencyjne jako źródła światła. W procesie tym wyznaczenie geometrii elementów oddziałujących na kierunki propagacji fali świetlnej odbywa się w oparciu o autorską metodę graficznego wykreślenia przebiegu promieni świetlnych i stycznych do powierzchni czynnych elementów w punktach koincydencji. Opracowanie rozpoczyna się od charakterystyki diod elektroluminescencyjnych pod kątem przydatności ich zastosowania w oprawach oświetleniowych. Następnie przedstawione są metody kształtowania rozsyłu strumienia świetlnego w oprawach wieloźródłowych. Opisane sąposzczególne elementy wykorzystywane do formowania bryły fotometrycznej. Przedstawiona jest własna metoda precyzyjnego doboru bryły fotometrycznej do konkretnych zastosowań oprawy. Opis metody graficznego wykreślania kształtu elementów optycznych zawiera wyprowadzenie idei metody z zasad optyki geometrycznej, przedstawienie opracowanych narzędzi projektowych oraz zastosowanie ich w praktyce. Ostatnim elementem pracy jest weryfikacja projektu w postaci komputerowych symulacji świecenia oprawy oraz wykonania pomiarów fotometrycznych oprawy wyposażonej w zaprojektowany układ optyczny i wykonania projektu wzorcowego. Rozprawa ma charakter praktyczny. Przydatność opisanej metody została potwierdzona wdrożeniem do produkcji zaprojektowanego zgodnie z nią elementu optycznego i powodzeniem rynkowym opraw, w których został on zaimplementowany.

EN

The introduction of light emitting diodes for lighting offered completely new quality in the construction of luminaires. Different production technology required new methods and design tools. The author's research on the development and practical application of his own method of luminaires design that use light emitting diodes as light sources was described in eight chapters of this work. Light emitting diodes were described as light sources useful for lighting. The construction and basic parameters of LEDs were characterized. The rules of creating expected luminous intensity distribution of the whole luminaire, realizing each, sometimes very complex, lighting task, were presented. Various methods were discussed of connecting components obtained from each set of LED with its light distributor in resultant luminous intensity distribution. The drawing method was discussed and proven; it consists of determining polylines (which are profiles of active surfaces) in a computer graphic environment with simple geometric tools. It was shown how luminous flux distribution of light sources and specific light distribution of optical components should be split into elementary rays to design the shapes of these elements without any problems. A design verification method through simulation of light distribution was shown. The main sources of calculation errors were indicated. The design process from the concept to the implementation of the LED luminaire was shown upon the example of road lighting. The methods and procedures used by the designer were described. Also, technological problems inftuencing introduction of the designed element to production were mentioned.

7

Study of structural, morphological, optical and electroluminescent properties of undoped ZnO nanorods grown by a simple chemical precipitation

Singh A., Vishwakarma H. L.

Materials Science Poland

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2015

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Vol. 33, No. 4

751--759

EN

In this work, zinc oxide (ZnO) nanorods were obtained by a simple chemical precipitation method in the presence of capping agent: polyvinyl pyrrolidone (PVP) at room temperature. X-ray diffraction (XRD) result indicates that the synthesized undoped ZnO nanorods have hexagonal wurtzite structure without any impurities. It has been observed that the growth direction of the prepared ZnO nanorods is [1 0 1]. XRD analysis revealed that the nanorods have the crystallite size of 49 nm. Crystallite size is calculated by Debye-Scherrer formula and lattice strain is calculated by Williomson-Hall equation. Cell volume, Lorentz factor, Lorentz polarization factor, bond length, texture coefficient, lattice constants and dislocation density have also been studied. We also compared the interplanar spacings and relative peak intensities with their standard values at different angles. The scanning electron microscope (SEM) images confirmed the size and shape of these nanorods. It has been found that the diameter of the nanorods ranges from 1.52 mu m to 1.61 mu m and the length is about 4.89 mu m. It has also been observed that at room temperature ultraviolet visible (UV-Vis) absorption band is around 355 nm (blue shifted as compared to the bulk). The average particle size has also been calculated by mathematical model of effective mass approximation equation, using UV-Vis absorption peak. Finally, the bandgap has been calculated using UV-absorption peak. Electroluminescence (EL) studies show that emission of light is possible at very small threshold voltage and it increases rapidly with increasing applied voltage. It is seen that smaller ZnO nanoparticles give higher electroluminescence brightness starting at lower threshold voltage. The brightness is also affected by increasing the frequency of AC signal.

8

Zmiany parametrów optycznych i elektrycznych diod laserowych na pasmo 808 nm i 880 nm w czasie długotrwałej pracy

Dąbrowska E., Teodorczyk M., Krzyżak K., Romaniec M., Sobczak G., Maląg A.

Materiały Elektroniczne

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2014

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T. 42, nr 3

5--10

PL

Zaprezentowane zostały zmiany parametrów optycznych i elektrycznych diod podczas długotrwałej pracy: zmniejszenie mocy wyjściowej, zwiększenie prądu progowego jak i zmiana długości fali emisji - dla diod na pasmo 880 nm w kierunku fal krótszych oraz dla diod na pasmo 808 nm w kierunku fal dłuższych.

EN

The following changes in optical and electrical parameters for diodes during long-term operation are presented: reduction in the output power, increase in the threshold current and change in the emission wavelength for diodes emitting at 880 nm towards shorter wavelengths and for diodes emitting at 808 nm towards longer wavelengths.

9

Obrazowane luminescencyjne do charakteryzacji ogniw i modułów fotowoltaicznych

Lipiński M., Kulesza G., Starowicz Z.

Elektronika : konstrukcje, technologie, zastosowania

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2014

|

Vol. 55, nr 8

52-54

PL

Obrazowanie fotoluminescencyjne i elektroluminescencyjne jest obecnie jedną z najważniejszych technik pomiarowych ogniw i modułów fotowoltaicznych. Trudno wyobrazić sobie dalszy rozwój technologii ogniw bez tego typu pomiarów. Technika ta pozwala również na kontrolę materiału wyjściowego (płytek Si typu „as-cut”) oraz płytek po każdym procesie technologicznym w produkcji ogniw i modułów co ma istotny wymiar ekonomiczny.

EN

Photoluminescence and electroluminescence imaging is one of the most important techniques for measuring solar cells and photovoltaic modules. It is extremely difficult to imagine the further development of cell technology without such measurements. This measurement also allows controlling of the starting material (“as-cut” Si wafers) and the plates after each technology process in the production of solar cells and modules, which is an important economic reason.

10

Electroluminescence of Y2O3:Eu and Y2O3:Sm films

Rodionov V. E., Shmidko I. N., Zolotovsky A. A., Kruchinin S. P.

Materials Science Poland

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2013

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Vol. 31, No. 2

232--239

EN

Electroluminescence of Y2O3:Eu and Y2O3:Sm films, as well as the films coactivated with Eu and Sm, is studied. The electroluminescence spectra are measured. The physical mechanism of electroluminescence is analyzed It is shown that the increase in the heat treatment temperature and the content of doping impurities of the films enhances the intensity of electroluminescence. Additional doping of Y2O3:EuF3 films by the SmF3 impurity, practically does not influence the emission spectrum.

11

Optical and electrical characterization of reverse bias luminescence in InGaN light emitting diodes

Chen H., Kao C. H., Lu T. C., Shei S. C.

Optica Applicata

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2011

|

Vol. 41, nr 1

195--205

EN

This study investigates the reliability physics of the reverse bias luminescence (RBL) of InGaN/GaN light emitting diodes. Optical and electrical characterization techniques including surface temperature measurements, 2D X-ray fluorescent element analysis, and 2D electroluminescence (EL) measurements reveal the leakage current distribution and the origin of the reverse bias leakage current. Using these techniques, this study examines the electroluminescence behavior and surface temperature distribution in forward bias and reverse bias conditions. Results show that the reverse bias EL originates from hot electron-induced emission, which in turn is due to the leakage current in the high electric field region caused by metal contact abnormalities. The optical and electrical characterization techniques adopted in this study are a promising screening tool for correlating device failures with fabrication processes.

12

Model matematyczny opisujący wpływ procesów starzeniowych na parametry elektroluminescencyjne struktur grubowarstwowych

Porada Z., Cież M.

Elektronika : konstrukcje, technologie, zastosowania

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2010

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Vol. 51, nr 6

123-125

PL

W artykule przedstawiono wyniki badań dotyczących wpływu czynników eksploatacyjnych (wilgoć, napięcie zasilania) na przebieg procesu starzenia grubowarstwowych struktur elektroluminescencyjnych. Autorzy zaproponowali nowy model matematyczny procesu starzenia, który określa w jakim stopniu proces ten wpływa na wartości współczynników B₀ i b w empirycznej zależności Alfrey'a-Taylora, opisującej luminancję B.

EN

The authors present in the paper the results of investigations concerning the influence of exploitational factors (humidity, supply voltage) on course of ageing process of thick film electroluminescent structures. Humidity performs the role of a medium conducting the ions and in result decomposes ZnS what leads to the deterioration of optical- electrical parameters of electroluminescent structures. It depicts to what degree the ageing process influences the value of B₀ and b coefficients in Alfrey-Taylor empirical equation connecting the luminance B with supply voltage and properties of materials composing the electroluminescent light source.

13

Model of ageing process of electroluminescent structures

Porada Z., Cież M., Prochwicz W.

Materiały Elektroniczne

|

2009

|

T. 37, nr 1

117-123

EN

In the presented paper the authors propose a new mathematical model of aging process proceeded in thick film electroluminescent structures. The impact of humidity, temperature and supply voltage parameters (amplitude, frequency) on luminance changes during long time exploitation tests was taken into consideration. It was observed that the electroluminophore in Destriau electroluminescent cells exhibit very fast decrease in luminance in the initial phase of exploitation. The results of investigations indicate that the increase of amplitude and frequency of supply voltage accelerate the aging process. The rate of the aging process is also significantly influenced by the ambient temperature and elevated humidity combined with a supply voltage. The proposed model enables to estimate the life-time of electroluminescent structures on a base of exploitation tests in their initial stage.

PL

Autorzy proponują w artykule nowy matematyczny model procesu starzenia zachodzącego w grubowarstwowych strukturach elektroluminescencyjnych. Uwzględniono wpływ wilgoci, temperatury i parametrów napięcia zasilającego (amplituda, częstotliwość) na zmiany luminancji podczas prób eksploatacyjnych. Zaobserwowano, że w początkowej fazie eksploatacji elektroluminofor w strukturach Destriau - warstwowych strukturach elektroluminescencyjnych, bardzo szybko zmniejsza luminancję. Wyniki badań wskazują, że wzrost wielkości amplitudy napięcia zasilającego i częstotliwości przyspiesza proces starzenia. Szybkość procesu starzenia struktur elektroluminescencyjnych w istotny sposób zależy od temperatury otoczenia i podwyższonej wilgotności w powiązaniu z napięciem zasilania. Zaproponowany model umożliwia oszacowanie czasu życia struktur elektroluminescencyjnych w oparciu o wyniki badań eksploatacyjnych, już w początkowej ich fazie.

14

The effect of DCJTB concentration on the photoluminescent and electroluminescent properties of PVK-PBD-perylene-DCJTB thin films

Cyap C. C., Yahaya M., Salleh M. M.

Materials Science Poland

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2009

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Vol. 27, No. 1

209--218

EN

The paper reports a study of photoluminescent (PL) and electroluminescent (EL) properties of PVK- PBD-perylene-DCJTB thin film with variation of DCJTB doping concentrations. Poly(9-vinylcarbazole) (PVK) functioned as polymeric hole-transporting host, 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD) as electron-transporting molecule, perylene as blue dopant, and 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7- tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) as a red dopant. The relative intensity of the blue emission from perylene decreased and that of the red emission from DCJTB increased with the increase of DCJTB concentration in both PL and EL spectra. However, the EL spectrum showed stronger DCJTB emission compared to the PL spectrum at the same DCJTB doping concentration, due to the carrier trapping effect. Interestingly, white light emission with C.I.E. coordinates of (0.31, 0.36) was observed in the EL spectrum when 0.05 wt. % of DCJTB was doped into PVK-PBD-perylene blend film. As a result, PVK-PBD-perylene-DCJTB thin film has potential application in white organic light emitting diodes.

15

Observation of electron injection in an organic field-effect transistor with electroluminescence

Ohshima Y., Kohn H., Lim E., Manaka T., Iwamoto M.

Materials Science Poland

|

2009

|

Vol. 27, No. 3

719--726

EN

A tetracene field-effect transistor (FET) with Au source and drain electrodes showed p-channel type behaviour, where the injected holes were the main carriers. Application of an ac electric field to the source electrode, while drain and gate electrodes were grounded, induced electroluminescence (EL) around the source electrode that was caused by alternating electron and hole injection. This result indicated that electron injection into tetracene was possible from a metal with a high work function such as Au. The application of an ac voltage superposed on a dc voltage showed that electron injection was assisted by the space-charge field that originated from holes accumulated around the source electrode.

16

Circular dichroism and electroluminescence of poly(diacetylene) film with chirality

Kohn H., Fukada M., Ohshima Y., Manaka T., Iwamoto M.

Materials Science Poland

|

2009

|

Vol. 27, No. 3

727--734

EN

By applying only circularly polarized light (CPL) irradiation to evaporated achiral diacetylene (DA) monomer film during its photopolymerization process, we prepared poly(diacetylene) (PDA) films that show circular dichroism (CD). The left- or right-handed chirality was induced in the polymerized PDA films by the left- and right-CPL irradiation. We studied physical properties of the prepared PDA films, including their electrical and optical properties. The induced chirality in PDA films was not destroyed after annealing at 353 K for 10 min, whilst their blue-phase was changed into a red one. The intensity of the CD signal was dependent on the substrate temperature employed for the monomer deposition. Electroluminescence was found to be enhanced with the polymerized PDA films installed as an active layer of organic field-effect transistors.

17

Właściwości elektroluminescencyjne niektórych układów heterocyklicznych z grupy 1H-pirazolo[3,4-b]chinolin

Gondek E., Daniel A., Pokladko M., Otowski W., Sanetra J., Mac M.

Czasopismo Techniczne. Nauki Podstawowe

|

2009

|

R. 106, z. 1-NP

85-93

PL

W artykule przedstawiono wyniki badań elektrooptycznych wybranych luminoforów z grupy układów azaheterocyklicznych. Zbudowano jednowarstwowe diody ITO/MOL+PVK/Ca/Al, w których warstwę aktywną stanowiła mieszanina luminofory z tej grupy oraz polimeru matrycowego PVK. Zebrano i omówiono właściwości fotofizyczne molekuł.

EN

In this paper the synthesis of some new chromophores which could be used in organic LED fabrication are presented. All of them are pyrazoloquinoline derivatives. They were characterized by absorption and photoemission spectroscopy. Some were used, dispersed in poly(N-vinylcarbazole) (PVK) matrix, as the emissive layer in LED structure.

18

Organic light emitting devices

Godlewski J., Obarowska M.

Opto-Electronics Review

|

2007

|

Vol. 15, No. 4

179-183

EN

The purpose of this paper is to provide general information about basic physical processes involved in organic electroluminescence and to present the main parameters and advantages of organic light emitting devices (OLEDs).

19

Large-dimensional light-emitting elements with printed electroluminophore

Cież M., Nowak S., Zaraska W., Porada Z.

Opto-Electronics Review

|

2007

|

Vol. 15, No. 3

159-162

EN

In the paper, the influence of design and manufacturing technology on the performance of large-dimensional light-emitting elements with screen-printed luminophore are presented. The luminophore is based on Cu activated and Cl co-activated zinc sulphide ZnS. A particular instability when exposed to moisture and at rated electric load has been abserved.

20

Technology of thick-film electroluminescent animated advertising

Cież M., Witek M., Korpak M., Prochowicz W., Zaraska K.

Electron Technology : Internet Journal

|

2005/2006

|

Vol.37/38, nr 11

1-3

EN

Because of the undeniable advantages of powder electroluminescent light sources the authors have designed and tested an animated thick film electroluminescent advertising panel. The paper describes the design steps and phases of the technological process. Finally, the brightness characteristics and influence of color translucent inks covering the segments are presented. The expected life time of the electroluminescent structure under normal exploitation conditions is evaluated.