Modeling the Effects of Emitter Doping Non-uniformity on the Internal Quantum Efficiency of Si-Drift Solar Cells

Author(s)

Abstract
The introduction of non-uniform doping profile in the quasi-neutral regions of a solar cell helps achieve better performance parameters such as higher conversion efficiency and improved current-voltage characteristics. However, a number of non-ideal effects becomes dominant as the doping level is increased; the transport parameters (i.e. mobility and lifetime) become doping and field dependent, the space-dependency of the bandgap narrowing becomes significant and the Auger recombination mechanism becomes dominant. These effects adversely affect the internal quantum efficiency and hence, need to be considered with great care. Unfortunately, owing to the evolving mathematical intractability, all these effects are not considered simultaneously in the existing models. This work focuses to develop an analytical model for a drift-field Si-solar cell with non-uniformly and heavily doped emitter region where the mathematical intractability problem has been resolved by employing an elegant approximation technique called "Exponential Approximation Technique". The developed model shows that the drift-field solar cells have significantly higher internal quantum efficiency over the uniformly-doped Si-solar cells, particularly for high energy photons.

Keywords
Drift-field solar cell, internal quantum efficiency, non-uniform doping profile

Cite this paper
Md. Yasin Javed Chowdhury, Md. Imrul Basher Chowdhury, Md. Iqbal Bahar Chowdhury, Modeling the Effects of Emitter Doping Non-uniformity on the Internal Quantum Efficiency of Si-Drift Solar Cells , SCIREA Journal of Electrics, Communication. Volume 1, Issue 2, December 2016 | PP. 49-61.

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