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Volume 7
Innovative Energy & Research
ISSN: 2576-1463
Advanced Energy Materials 2018
August 13-14, 2018
August 13-14, 2018 | Dublin, Ireland
20
th
International Conference on
Advanced Energy Materials and Research
Multi-striped orthogonal photon-photo carrier-propagation solar cells (MOP
3
SCs) with new
asymmetric redirection waveguides
Akira Ishibashi
Research Institute for Electronic Science - Hokkaido University, Japan
I
n orthogonal photon-photo carrier propagation solar cell (MOP
3
SC), photons propagate in the direction orthogonal to
that of the photo carriers. Photons being absorbed in the direction vertical to that of the carrier drift/diffusion, trade-
off between photon absorption and carrier collection can be lifted. We can set the stripe-width large enough to absorb all
the photons keeping the distance between the p/n electrode distance (= semiconductors layer thickness) short enough to
allow most of photo carriers to reach out to the contact metals. Further, by placing those multiple semiconductor stripes,
neighboring to each other, with different band-gaps in such an order that the incoming photons first encounter the widest gap
semiconductor, then medium-gap ones, and the narrowest at last, we can convert the whole solar spectrum into electricity
resulting in high conversion efficiency. The multi-striped solar cell structure is placed at the edge of redirection waveguide
in which 3D-propagation photons are redirected to be 2D photons propagating in the waveguide. The waveguide-coupled
MOP
3
SC serves as a concentration photovoltaic system typically operating under a few hundreds to a thousand suns. Using an
integrated-paraboloid-sheet as the first layer of the redirection waveguide, we can make the daytime sunlight virtually impinge
the rest of the waveguide structure at a right angle. Further, asymmetric waveguide-coupled MOP
3
SC serves as a highly efficient
concentration photovoltaic system thanks to the low temperature rise due to the minimal thermal dissipation and the diffusive
light convertibility thanks to the integrated-paraboloid-sheet. The system is also of interest as a high reliability system, because
those photons that can damage the bonding of the materials, being converted into electricity already at upstream, never go into
the medium or narrow gap semiconductors. Thus, the asymmetric waveguide-coupled MOP
3
SC would serve as an ultimate
high efficiency all-in-one system in the near future.
Figure 1:
Waveguide-coupled multi-striped orthogonal photon-photocarrier-propagation solar cell (MOP
3
SC), the cross-section of MOP
3
SC with the periodic
parabolic mirrors (down left), and a simulation result for an example of asymmetric waveguide [tapered WG] (down right). The total width of the multi-striped
semiconductor is tens to hundreds of microns.
Recent Publications
1.
Ishibashi A, White S, Kawaguchi N, Kondo K and Kasai T (2016) Edge-illumination scheme for multi-striped orthogonal
photon-photo carrier - propagation solar cells, Int. J. Eng. Tech. Res. 6(1):115-117.
2.
Ishibashi A, Kobayashi H, Taniguchi T, Kondo K and Kasai T (2016) Optical simulation for multi-striped orthogonal photon
- photo carrier-propagation solar cell (MOP
3
SC) with redirection waveguide. 3D Research 7:33.
3.
Ishibashi A (2016) Orthogonal photon-photo carrier - propagation solar cells, (in Japanese) Energy Devices 3(4): pp. 77-83.
Biography
Akira Ishibashi received the BSc, MSc and PhD degrees in Physics in 1981, 1983, and 1990, respectively, all from the University of Tokyo, Japan. During 1982–1983,
he was a Research Assistant at LBNL, Berkeley, USA. In 1983, he joined the Research Center of Sony Corporation, Yokohama. He was a Visiting Faculty at Loomis
Laboratory, Department of Physics, University of Illinois at Urbana-Champaign, 1990-1991. In Sony he achieved world-first RT CW operation of blue/green laser diodes
using ZnMgSSe, in 1993. He was a Visiting Professor at Center for Interdisciplinary Research, Tohoku University, Japan in 1998. Since 2003 he has been a full Professor
in leading Nanostructure Physics Lab in RIES, Hokkaido University, Japan. In 2006, he started Hokkaido University Venture Company, C’sTEC Corp., based on Clean Unit
System Platform (CUSP). His main target is to realize high-efficiency solar cells exploiting CUSP that helps people live in a high standard.
i-akira@es.hokudai.ac.jpAkira Ishibashi, Innov Ener Res 2018, Volume 7
DOI: 10.4172/2576-1463-C1-002