Design of Radial pin Si Nanowires for High Performance Solar Cells

Conference · Mon Sep 03 00:00:00 EDT 2012

OSTI ID:1050473

Nguyen, Binh-Minh ^[1]; Yoo, Jinkyoung ^[1]; Dayeh, Shadi ^[1]; Picraux, Samuel Thomas ^[1]

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1. Los Alamos National Laboratory

The quantum efficiency of solar cells, like of any photon detector, is dictated by the ability to absorb photons to create conducting carriers, and the efficiency to drive such carriers to electrodes for collection. Having a medium that enables full photon absorption in a short length, together with a long carrier lifetime that allows photo-generated carriers to reach electrodes before recombining are ideal, but are not always realistic. For example, silicon photovoltaics, despite being a major player in the solar cell market, suffer from the low absorption coefficient, thus requiring a thick absorbing layer which impairs the efficiency with which photogenerated carriers are collected. Radial silicon nanowires have been proposed as a candidate for reducing the optical absorption length and required processing purity in Si based solar cells without compromising their quantum efficiency and yet reducing the overall cell cost. On the one hand, incident light propagates along the axial dimension of the wires, and thus has a greater chance of being absorbed when the wire length extends beyond 10m due to inter-array light scattering effects. On the other hand, the core/shell p-i-n structure leads electrical current flow along sub-micron radii, which enables rapid collection of most photogenerated carriers as the transport length is typically less than the diffusion lengths of minority carriers. In this work, we perform Finite Difference Time Domain (FDTD) simulation to investigate the absorption process in arrayed radial nanowires.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: DOE/LANL
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1050473
• Report Number(s): LA-UR-12-24461; TRN: US201218%%1471
• Resource Relation: Conference: Infrared Optoelectronics: Materials and Devices ; 2012-09-04 - 2012-09-04 ; Chicago, Illinois, United States
• Country of Publication: United States
• Language: English

Related Subjects

Energy Sciences
Material Science
Engineering(42)
Materials Science(36)
Nanoscience & Nanotechnology(77)
ABSORPTION
CARRIER LIFETIME
CHARGE CARRIERS
DESIGN
DIFFUSION LENGTH
EFFICIENCY
FINITE DIFFERENCE METHOD
LENGTH
LIGHT SCATTERING
NANOSTRUCTURES
PERFORMANCE
PHOTONS
QUANTUM EFFICIENCY
SILICON
SOLAR CELLS