On the Nature of Shunt Leakage in Amorphous Silicon p-i-n Solar Cells

Dongaonkar, Sourabh; Yogendra, Karthik; Wang, Dapeng; Frei, M.; Mahapatra, S.; Alam, Muhammad A.

doi:10.1109/led.2010.2064754

Cited by 26 publications

(18 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The range of γ was found to be 1 < γ < 2, reflecting the space charge limited transport [23], [24]. The excellent uniformity of the prefactors (G Sh , J 0Sh ) for the measured samples, as summarized in Table I, indicates the process uniformity.…”

Section: A Experimental Observationsmentioning

confidence: 77%

“…The P + a-Si emitter and an intrinsic a-Si buffer layer The shunt parameters are extracted from the measured dark I-V data using the method developed in [24]. The n MFB indicate abnormally high ideality factors (n MFB >> 2).…”

Section: A Experimental Observationsmentioning

confidence: 99%

“…Next, the forward-bias dark I-V is "cleaned" by subtracting the effects of the parasitic shunt current by using the "reflection" method suggested in [24] and [25]; this allows consideration of the intrinsic I-V features uncontaminated by shunt conduction. A typical shunt-corrected forward-bias dark I-V characteristics (of sample A) is shown in Fig.…”

Section: A Experimental Observationsmentioning

confidence: 99%

See 2 more Smart Citations

Correlated Nonideal Effects of Dark and Light I–V Characteristics in a-Si/c-Si Heterojunction Solar Cells

Chavali

Wilcox

Ray

et al. 2014

IEEE J. Photovoltaics

View full text Add to dashboard Cite

a-Si/c-Si (amorphous Silcon/crystalline Silicon) heterojunction solar cells exhibit several distinctive dark and light I-V nonideal features. The dark I-V of these cells exhibits unusually high ideality factors at low forward-bias and the occurrence of a "knee" at medium forward-bias. Nonidealities under illumination, such as the failure of superposition and the occurrence of an "S-type" curve, are also reported in these cells. However, the origin of these nonidealities and how the dark I-V nonidealities manifest themselves under illumination, and vice versa, have not been clearly and consistently explained in the current literature. In this study, a numerical framework is used to interpret the origin of the dark I-V nonidealities, and a novel simulation technique is developed to separate the photo-current and the contact injection current components of the light I-V. Using this technique, the voltage dependence of photo-current is studied to explain the failure of the superposition principle and the origin of the S-type light I-V characteristics. The analysis provides a number of insights into the correlations between the dark I-V and the light I-V. Finally, using the experimental results from this study and from the current literature, it is shown that these nonideal effects indeed affect the dark I-V and the light I-V in a predictable manner.

show abstract

Section: A Experimental Observationsmentioning

confidence: 77%

Section: A Experimental Observationsmentioning

confidence: 99%

Section: A Experimental Observationsmentioning

confidence: 99%

See 1 more Smart Citation

Correlated Nonideal Effects of Dark and Light I–V Characteristics in a-Si/c-Si Heterojunction Solar Cells

Chavali

Wilcox

Ray

et al. 2014

IEEE J. Photovoltaics

View full text Add to dashboard Cite

show abstract

“…2b includes a non-Ohmic shunt current element with power law voltage dependence; i.e. I SH = I SH0 V β , where power exponent β is about 2-3 [8]. Moreover, it has been reported that the magnitude I SH0 at subcell level in TFPV follows a lognormal distribution, as shown in Fig.…”

Section: A Physics and Statistics Of Shunt Currentmentioning

confidence: 96%

“…And, the power exponents and effective mobility µ c are determined by the trap distribution inside the bandgap (characterized by the parameter γ) [8]. These intrinsic shunts are typically formed due to local metal incursion in absorber layers through thin emitter layers, and show similar SCL behavior for different thin film PV technologies [9].…”

Section: Simulation Frameworkmentioning

confidence: 99%

End to end modeling for variability and reliability analysis of thin film photovoltaics

Dongaonkar

Alam

2012

2012 IEEE International Reliability Physics Symposium (IRPS)

Self Cite

View full text Add to dashboard Cite

We present an end-to-end modeling framework, spanning the device, module and also system levels, for analyzing thin film photovoltaics (PV). This approach is based on embedding a detailed, statistically relevant, physics based equivalent circuit into module and array level simulations. This approach enables us to analyze key variability and reliability issues in thin film PV, and allows us to interpret their effect on process yield and intrinsic module lifetimes. Our results suggest that the time-zero gap between cell and module efficiencies, a key variability concern for thin-film PV, can be attributed to processrelated shunts with log-normal PDF distributed randomly across the cell surface. Similarly, this end-to-end simulation approach allows us to investigate the reliability issues caused by partial shadowing in thin film modules, especially in context of array configurations. These results provide important insights into its nature and consequences of shadow degradation on long term system performance. This work showcases the importance of an integrated analysis in case of thin film PV, because traditional approaches used to Silicon PV to tackle reliability/variability issues cannot be applied directly to such systems.

show abstract

Geometrical design of thin film photovoltaic modules for improved shade tolerance and performance

Dongaonkar

Alam

2013

Progress in Photovoltaics

Self Cite

View full text Add to dashboard Cite

Partial shading in photovoltaic modules is an important reliability and performance concern for all photovoltaic technologies. In this paper, we show how cell geometry can be used as a design variable for improved shade tolerance and performance in monolithic thin film photovoltaic modules (TFPV). We use circuit simulations to illustrate the geometrical aspects of partial shading in typical monolithic TFPV modules with rectangular cells, and formulate rules for shade tolerant design. We show that the problem of partial shading can be overcome by modifying the cell shape and orientation, while preserving the module shape and output characteristics. We discuss two geometrical designs with cells arranged in radial and spiral patterns, which (i) prevent the reverse breakdown of partially shaded cells, (ii) improve the overall power output under partial shading, and (iii) in case of spiral design, may additionally improve the module efficiency by reducing sheet resistance losses. We compare these designs quantitatively using realistic parameters and discuss the practical aspects for their implementation. Copyright © 2013 John Wiley & Sons, Ltd.

show abstract

On the Nature of Shunt Leakage in Amorphous Silicon p-i-n Solar Cells

Cited by 26 publications

References 12 publications

Correlated Nonideal Effects of Dark and Light I–V Characteristics in a-Si/c-Si Heterojunction Solar Cells

Correlated Nonideal Effects of Dark and Light I–V Characteristics in a-Si/c-Si Heterojunction Solar Cells

End to end modeling for variability and reliability analysis of thin film photovoltaics

Geometrical design of thin film photovoltaic modules for improved shade tolerance and performance

Contact Info

Product

Resources

About