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Electrical and Computer Engineering

Selected Works

2013

Reliability

Articles 1 - 3 of 3

Full-Text Articles in Engineering

End-To-End Modeling For Variability And Reliability Analysis Of Thin Film Pv, Sourabh Dongaonkar, Muhammad Alam Mar 2013

End-To-End Modeling For Variability And Reliability Analysis Of Thin Film Pv, Sourabh Dongaonkar, Muhammad Alam

Sourabh Dongaonkar

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 …


A Physical Model For Non-Ohmic Shunt Conduction And Metastability In Amorphous Silicon P-I-N Solar Cells, Sourabh Dongaonkar, Karthik Y, Souvik Mahapatra, Muhammad Alam Mar 2013

A Physical Model For Non-Ohmic Shunt Conduction And Metastability In Amorphous Silicon P-I-N Solar Cells, Sourabh Dongaonkar, Karthik Y, Souvik Mahapatra, Muhammad Alam

Sourabh Dongaonkar

We present a physical model of non-ohmic shunt current in a-Si:H p-i-n solar cells, and validate it with detailed measurements. This model is based on space-charge-limited (SCL) transport through localized p-i-p shunt paths, which can arise from contact metal incorporation in a-Si:H layer. This model explains both the electrical characteristics and the metastable switching behavior of the shunts within an integrated framework. We first verify the SCL model using simulations and statistically robust measurements, and then use this picture to analyze our systematic observations of non-volatile switching in these shunts. Our work not only resolves broad experimental observations on shunt …


Identification, Characterization, And Implications Of Shadow Degradation In Thin Film Solar Cells, Sourabh Dongaonkar, Karthik Y, Dapeng Wang, Michel Frei, Souvik Mahapatra, Muhammad Alam Mar 2013

Identification, Characterization, And Implications Of Shadow Degradation In Thin Film Solar Cells, Sourabh Dongaonkar, Karthik Y, Dapeng Wang, Michel Frei, Souvik Mahapatra, Muhammad Alam

Sourabh Dongaonkar

We describe a comprehensive study of intrinsicreliability issue arising from partial shadowing of photovoltaicpanels (e.g., a leaf fallen on it, a nearby tree casting a shadow,etc.). This can cause the shaded cells to be reverse biased, causingdark current degradation. In this paper, (1) we calculate thestatistical distribution of reverse bias stress arising from variousshading configurations, (2) identify the components of darkcurrent, and provide a scheme to isolate them, (3) characterizethe effect of reverse stress on the dark current of a-Si:H p-i-ncells, and (4) finally, combine these features of degradationprocess with shadowing statistics, to project ‘shadow-degradation’ (SD) over the operating lifetime …