Light trapping effect from randomized textures of Ag/ZnO back reflector on hydrogenated amorphous and nanocrystalline silicon based solar cells

Baojie Yan; Guozhen Yue; Laura Sivec; Jessica M. Owens; Ken Lord; Jeffrey Yang; Subhendu Guha; Chun-Sheng Jiang

doi:10.1117/12.859867

1 September 2010 Light trapping effect from randomized textures of Ag/ZnO back reflector on hydrogenated amorphous and nanocrystalline silicon based solar cells

Baojie Yan, Guozhen Yue, Laura Sivec, Jessica M. Owens, Ken Lord, Jeffrey Yang, Subhendu Guha, Chun-Sheng Jiang

Author Affiliations +

Proceedings Volume 7771, Thin Film Solar Technology II; 777102 (2010) https://doi.org/10.1117/12.859867
Event: SPIE Solar Energy + Technology, 2010, San Diego, California, United States

Abstract

We report our progress in the optimization of Ag/ZnO back reflectors (BR) for a-Si:H and nc-Si:H solar cells. Theoretically, a BR with a smooth metal surface and a textured dielectric surface would be more desirable. A smooth metal/dielectric interface reduces the plasmonic resonance loss and parasitic losses due to light trapped in sharp angles; a textured dielectric/semiconductor interface provides scattering for light trapping. In order to obtain sufficient light scattering at the ZnO/silicon interface, a highly textured ZnO layer is normally used. However, a highly textured ZnO surface causes deterioration of nc-Si:H material quality. In addition, to make a highly textured ZnO surface, a thick ZnO layer is needed, which could introduce additional absorption in the bulk ZnO layer and reduce the photocurrent density. Therefore, Ag/ZnO BR structures for nc-Si:H solar cells needs to be optimized experimentally. In this study, we found that an optimized Ag/ZnO BR for nc-Si:H solar cells is constructed with textured Ag and thin ZnO layers. Although a textured Ag layer might cause certain losses resulting from plasmonic absorption, the enhanced light scattering by a moderately textured Ag layer makes it possible to use a thin ZnO layer, where the absorption in the ZnO layer is low. With such a BR, we achieved a short-circuit current density of over 29 mA/cm² from a nc-Si:H single-junction solar cell. Using the high performance nc-Si:H cell in an a-Si:H/nc- Si:H/nc-Si:H triple-junction structure, we achieved an initial active-area efficiency of 14.5% with a total current density exceeding 30 mA/cm2.

Citation Download Citation

Baojie Yan, Guozhen Yue, Laura Sivec, Jessica M. Owens, Ken Lord, Jeffrey Yang, Subhendu Guha, and Chun-Sheng Jiang "Light trapping effect from randomized textures of Ag/ZnO back reflector on hydrogenated amorphous and nanocrystalline silicon based solar cells", Proc. SPIE 7771, Thin Film Solar Technology II, 777102 (1 September 2010); https://doi.org/10.1117/12.859867

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available