Limits...
Performance evaluation of multi-junction solar cells by spatially resolved electroluminescence microscopy.

Kong L, Wu Z, Chen S, Cao Y, Zhang Y, Li H, Kang J - Nanoscale Res Lett (2015)

Bottom Line: Meanwhile, we analyzed the relationship between electroluminescence intensity and short-circuit current density J SC.The results indicated that the gray value of the electroluminescence image corresponding to the intensity was almost proportional to J SC.This technology provides a potential way to evaluate the current matching status of multi-junction solar cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005 People's Republic of China.

ABSTRACT
An electroluminescence microscopy combined with a spectroscopy was developed to visually analyze multi-junction solar cells. Triple-junction solar cells with different conversion efficiencies were characterized by using this system. The results showed that the mechanical damages and material defects in solar cells can be clearly distinguished, indicating a high-resolution imaging. The external quantum efficiency (EQE) measurements demonstrated that different types of defects or damages impacted cell performance in various degrees and the electric leakage mostly degraded the EQE. Meanwhile, we analyzed the relationship between electroluminescence intensity and short-circuit current density J SC. The results indicated that the gray value of the electroluminescence image corresponding to the intensity was almost proportional to J SC. This technology provides a potential way to evaluate the current matching status of multi-junction solar cells.

No MeSH data available.


Related in: MedlinePlus

EL images of GaInP (a) and GaInAs (b) subcells of cell A under a forward bias of 2.0 V.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4385041&req=5

Fig4: EL images of GaInP (a) and GaInAs (b) subcells of cell A under a forward bias of 2.0 V.

Mentions: Figure 4 shows the EL images of cell A under a forward bias of 2.0 V. As shown in Figure 4a, almost no luminescence is observed for the GaInP top cell except at the upper left corner where the local intensity is very strong. It is noted that an extremely bright emission in the same position was found for the GaInAs middle cell in Figure 4b. Considering the injected current of 320 mA, it is believed that this solar cell has been badly impaired due to electric leakage, which agrees well with the above prediction. The degradation of the I-V parameters was mainly caused by a low shunt resistance and the increased current density in the upper left part. As for the top cell, the high current density spreading to the lower junction overcompensates the leakage defect, which leads to a dark EL image over the cell.Figure 4


Performance evaluation of multi-junction solar cells by spatially resolved electroluminescence microscopy.

Kong L, Wu Z, Chen S, Cao Y, Zhang Y, Li H, Kang J - Nanoscale Res Lett (2015)

EL images of GaInP (a) and GaInAs (b) subcells of cell A under a forward bias of 2.0 V.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385041&req=5

Fig4: EL images of GaInP (a) and GaInAs (b) subcells of cell A under a forward bias of 2.0 V.
Mentions: Figure 4 shows the EL images of cell A under a forward bias of 2.0 V. As shown in Figure 4a, almost no luminescence is observed for the GaInP top cell except at the upper left corner where the local intensity is very strong. It is noted that an extremely bright emission in the same position was found for the GaInAs middle cell in Figure 4b. Considering the injected current of 320 mA, it is believed that this solar cell has been badly impaired due to electric leakage, which agrees well with the above prediction. The degradation of the I-V parameters was mainly caused by a low shunt resistance and the increased current density in the upper left part. As for the top cell, the high current density spreading to the lower junction overcompensates the leakage defect, which leads to a dark EL image over the cell.Figure 4

Bottom Line: Meanwhile, we analyzed the relationship between electroluminescence intensity and short-circuit current density J SC.The results indicated that the gray value of the electroluminescence image corresponding to the intensity was almost proportional to J SC.This technology provides a potential way to evaluate the current matching status of multi-junction solar cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005 People's Republic of China.

ABSTRACT
An electroluminescence microscopy combined with a spectroscopy was developed to visually analyze multi-junction solar cells. Triple-junction solar cells with different conversion efficiencies were characterized by using this system. The results showed that the mechanical damages and material defects in solar cells can be clearly distinguished, indicating a high-resolution imaging. The external quantum efficiency (EQE) measurements demonstrated that different types of defects or damages impacted cell performance in various degrees and the electric leakage mostly degraded the EQE. Meanwhile, we analyzed the relationship between electroluminescence intensity and short-circuit current density J SC. The results indicated that the gray value of the electroluminescence image corresponding to the intensity was almost proportional to J SC. This technology provides a potential way to evaluate the current matching status of multi-junction solar cells.

No MeSH data available.


Related in: MedlinePlus