Intermediate band photovoltaics based on interband–intraband transitions using In0.53Ga0.47As/InP superlattice

Authors

  • Weiguo Hu,

    Corresponding author
    • Center for Collaborative Research and Technology Development (CREATE), Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
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  • Yukihiro Harada,

    1. Center for Collaborative Research and Technology Development (CREATE), Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
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  • Aiko Hasegawa,

    1. Center for Collaborative Research and Technology Development (CREATE), Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
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  • Tomoya Inoue,

    1. Center for Collaborative Research and Technology Development (CREATE), Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
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  • Osamu Kojima,

    1. Center for Collaborative Research and Technology Development (CREATE), Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
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  • Takashi Kita

    1. Center for Collaborative Research and Technology Development (CREATE), Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
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Correspondence: Weiguo Hu, Center for Collaborative Research and Technology Development (CREATE), Department of Electrical and Electronic Engineering, Kobe University, Rokkodai 1-1, Nada, Kobe 657-8501, Japan.

E-mail: weiguohu09@gmail.com

ABSTRACT

We present a theoretical model to incorporate the quantum mechanism of two-photon transitions into macroscopic operations. The two-photon transition is described as a two-step interband–intraband transition within the one-band envelope-function framework and is coupled with drift–diffusion as well as the potential distribution. In0.53Ga0.47As/InP superlattices (SLs) are chosen as the initial candidate to simulate intermediate band solar cell operation. In this type of structure, the absorption spectrum of interband and intraband transitions is asymmetric and strongly depends on device structure and operating conditions. Our results also reveal that the intraband transition dominates the detailed balance. Both the intermediate band (IB) configuration and the conversion efficiency are determined by the SL structure. Only well-designed SLs can form the appropriate IB. Furthermore, an efficiency contour plot has been calculated to guide quantum design: the peak efficiency is 45.61% when the well thickness is 4 nm and the barrier thickness is 2 nm. As the well or barrier thickness increases to 10 nm, the absorption peak of the intraband transition gradually redshifts and narrows, so the efficiency correspondingly decreases to below 40%. Copyright © 2011 John Wiley & Sons, Ltd.

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