Transient phenomena in Cu(In,Ga)Se2 solar modules investigated by electroluminescence imaging

Tran, Thi Minh Hang; Pieters, Bart E.; Ulbrich, Carolin; Gerber, Andreas; Kirchartz, Thomas; Rau, Uwe

doi:10.1016/j.tsf.2012.10.039

Cited by 17 publications

(11 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A four point measurement setup was used to minimize the influence of the contact resistance. The sample was held at a constant temperature of 25 C during all the measurements via Peltier elements and water cooling. The luminescence images were taken with a Princeton Instruments Nirvana640 InGaAs camera (640 Â 512 pixels) cooled to À80 C. For the EM-PL images, the sample was held under constant illumination using a 90 W, 808 nm diode laser, with an intensity of 1 sun equivalent.…”

Section: B Experimental Resultsmentioning

confidence: 99%

“…This gradient results from the different sheet resistances of the front and back contacts. 25 As the TCO has a higher sheet resistance than the Mo back contact, the photocurrent collection decreases in one direction as the collected current needs to transverse larger distances through the TCO. This effect is very similar to the change of the local voltage one sees in simple EL images but now we can quantify its influence on the charge carrier collection properties, e.g., under these conditions the probability for additionally generated charge carriers to contribute to the external current is nearly three times lower when they are generated on the right side of the cell as compared to charge carriers generated on the left side of the cell.…”

Section: B Experimental Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Cu(In,Ga)Se2 thin-film modules by electro-modulated luminescence

Huhn

Gerber

Augarten

et al. 2016

Journal of Applied Physics

View full text Add to dashboard Cite

Thin-film Cu(In,Ga)Se2 modules are investigated by electro-modulated luminescence with bias illumination. The large signal analysis enables the determination of the average current density/voltage (J/V) characteristics of individual cell-stripes in a module, without contacting each individual cell. It was found that the characteristics determined from electro-modulated photo-luminescence measurements differ from the characteristics determined without bias illumination via electro-luminescence. As a reason for this, we found the non-linear relation of the local current to the local voltage which makes the determination of the cell voltage via an average of the local voltages determined from electro-luminescence images incorrect especially at high injection currents. A second analysis method using the small signal response of electro-modulated photo-luminescence was also analyzed. Recently, a method based on such a small signal analysis was demonstrated that yields the local photocurrent collection efficiency. This contribution presents the first application of this method to solar modules with series connected cells rather than the previously shown analysis of single cells. We compare two ways to evaluate the photocurrent collection efficiency from the small signal analysis and discuss how applicable these measurements are to modules. We find that the photocurrent collection efficiency of modules gives valuable information about how defective cells act within a module and which parts of the module limit the overall current through the module.

show abstract

Section: B Experimental Resultsmentioning

confidence: 99%

Section: B Experimental Resultsmentioning

confidence: 99%

Analysis of Cu(In,Ga)Se2 thin-film modules by electro-modulated luminescence

Huhn

Gerber

Augarten

et al. 2016

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…Light soaking was performed at an elevated temperature T LS = 400 K for 3 h with illumination intensity of approximately 1 sun to ensure that we arrive at a saturated state. For the spatially resolved EL partly reported [33] the modules were kept in the dark overnight at room temperature prior to the transient measurements. EL pictures were taken during applied current or voltage bias every 5 seconds at ambient temperature using a Si-CCD camera.…”

Section: Methodsmentioning

confidence: 99%

Electroluminescence of Cu(In,Ga)Se₂ solar cells and modules

et al. 2013

Self Cite

View full text Add to dashboard Cite

Fundamental aspects of (electro-)luminescence of Cu(In,Ga)Se 2 solar cells and modules are investigated by means of spectrally and spatially resolved measurements. The validity of the reciprocity relation between spectrally resolved electroluminescence emission and photovoltaic quantum efficiency is verified for the case of industrially produced ZnO/CdS/Cu(In,Ga)Se 2 heterojunction solar cells. Further we find that photo-and electroluminescent emission in these devices obey a superposition principle only in a limited range of the applied electrical or illumination bias. This range depends on the light soaking history of the sample and extends up to an injected current density of approximately 15 mAcm -2 after 3 h of light soaking at a temperature of 400 K. In the state prior to light soaking this range is limited to 4 mAcm -2 . At higher bias, a characteristic discrepancy between electroluminescence and electro-modulated photoluminescence appears. We attribute this anomaly to a potential barrier behavior close to the CdS/ Cu(In,Ga)Se 2 interface. Metastable defect reactions induced by holes injected into the space charge region partly reduce this barrier. We further find that the luminescence efficiency is enhanced by a factor of 3 by light soaking at 400 K. Spatially resolved electroluminescence measurements conducted during application of voltage or current bias at ambient temperature in the dark are qualitatively compatible with the conclusions drawn from the spectrally resolved measurements.

show abstract

“…We perform our EL measurements with a full-frame Si-CCD camera with a 3000 × 3000 pixel sensor [18], [19], while our DLIT setup contains an IR-thermography camera with a 384 × 288 pixel sensor [4]. In order to minimize the influence of metastable tranciences [19], we keep a pause period of several minutes before each EL and DLIT measurement until δV /δt ≈ 0.…”

Section: B Electroluminescence and Dark Lock-in Thermography Setupmentioning

confidence: 99%

“…In order to minimize the influence of metastable tranciences [19], we keep a pause period of several minutes before each EL and DLIT measurement until δV /δt ≈ 0. Based on the optimum lock-in parameter regions found in [15, pp.…”

Section: B Electroluminescence and Dark Lock-in Thermography Setupmentioning

confidence: 99%

Defect Diagnostics of Scribing Failures and Cu-Rich Debris in Cu(In,Ga)Se<inline-formula><tex-math>$_2$ </tex-math></inline-formula> Thin-Film Solar Modules With Electroluminescence and Thermography

Misic

Pieters

Schweitzer

et al. 2015

IEEE J. Photovoltaics

View full text Add to dashboard Cite

We study the appearance of both scribing failures and Cu-rich debris, formed during Cu(In,Ga)Se 2 (CIGS) coevaporation, in electroluminescence (EL) and dark lock-in thermography (DLIT) images. We observe that for most of the defect types, there is a characteristic appearance of EL and DLIT that allows reliable diagnostics. We also point to defect scenarios where different defects appear similar. With regard to scribing defects, we find that the reliability of defect identification increases with the length of the line interruption, while for Cu-rich debris, we find that the geometrical size and position within the cell significantly determine its defect appearance and, therefore, the ability to diagnose it.

show abstract

Transient phenomena in Cu(In,Ga)Se2 solar modules investigated by electroluminescence imaging

Cited by 17 publications

References 17 publications

Analysis of Cu(In,Ga)Se2 thin-film modules by electro-modulated luminescence

Analysis of Cu(In,Ga)Se2 thin-film modules by electro-modulated luminescence

Electroluminescence of Cu(In,Ga)Se₂ solar cells and modules

Defect Diagnostics of Scribing Failures and Cu-Rich Debris in Cu(In,Ga)Se<inline-formula><tex-math>$_2$ </tex-math></inline-formula> Thin-Film Solar Modules With Electroluminescence and Thermography

Contact Info

Product

Resources

About

Transient phenomena in Cu(In,Ga)Se2 solar modules investigated by electroluminescence imaging

Cited by 17 publications

References 17 publications

Analysis of Cu(In,Ga)Se2 thin-film modules by electro-modulated luminescence

Analysis of Cu(In,Ga)Se2 thin-film modules by electro-modulated luminescence

Electroluminescence of Cu(In,Ga)Se2 solar cells and modules

Defect Diagnostics of Scribing Failures and Cu-Rich Debris in Cu(In,Ga)Se<inline-formula><tex-math>$_2$ </tex-math></inline-formula> Thin-Film Solar Modules With Electroluminescence and Thermography

Contact Info

Product

Resources

About

Electroluminescence of Cu(In,Ga)Se₂ solar cells and modules