Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Parametric study of micropillar array solar cells



Heayoung Yoon, Yu A. Yuwen, Haoting Shen, Nikolas J. Podraza, Thomas E. Mallouk, Elizabeth C. Dickey, Joan A. Redwing, Christopher R. Wronski, Theresa S. Mayer


Micro/nano pillar arrays can be a promising architecture for high efficiency solar cells based on less expensive photovoltaic materials with short minority carrier diffusion lengths (Ln, p). To investigate design tradeoffs of the radial junction array solar cells, we fabricated 25 µm-tall c-Si pillar array devices having different diameters and pillar filling ratio. The high-aspect-ratio radial p+-n+ junctions were formed by gas phase diffusion of an n-type dopant into etched p-type Si pillars. The c-Si pillar arrays showed clear rectifying properties. The spectral reflectance decreased with the pillar filling ratio increase from 0.2 to 0.5, but no subsequent decrease was observed above the filling ratio of 0.5. On the other hand, approximately two times higher cell efficiency was obtained with an 8 µm diameter (3 Ln) pillar array having the same pillar filling ratio.
Conference Dates
June 19-24, 2011
Conference Location
Seattle, WA
Conference Title
Photovoltaic Specialist Conferences, 2011


etched pillar array, solar cells, microwire, silicon


Yoon, H. , Yuwen, Y. , Shen, H. , Podraza, N. , Mallouk, T. , Dickey, E. , Redwing, J. , Wronski, C. and Mayer, T. (2011), Parametric study of micropillar array solar cells, Photovoltaic Specialist Conferences, 2011, Seattle, WA, [online], (Accessed June 14, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created June 19, 2011, Updated February 19, 2017