Enhanced optical absorption in a thin silicon layer with nanovoids

Authors: Banerjee, M.; Datta, S.K.; Saha, H.

Source: Nanotechnology, Volume 16, Number 9, September 2005 , pp. 1542-1548(7)

Publisher: Institute of Physics Publishing

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content

Abstract:

A detailed theory for enhanced optical absorption in thin silicon with a distribution of nanovoids has been worked out in this paper. It is demonstrated that significant enhancement of the effective optical absorption coefficient (by a factor of about two to more than four) in a thin Si layer can be achieved by optimizing the dimensions and distribution of nanovoids. In this work, the absorption in a thin Si layer has been modelled taking into account the diffraction of light by the nanocrystallites between the voids as well as the scattering of light by the voids. This modelling is supposed to be applicable to any semiconductor film having a distribution of nanovoids since the modelling incorporates scattering phenomena due to Rayleigh scattering for small voids and the gradual transition from Rayleigh scattering to diffraction phenomena in the case of large voids including multiple-and back-scattering effects. The consideration of the diffraction of light instead of Mie scattering greatly simplifies the calculation and still predicts the correct behaviour of absorption phenomena in such films. The simulated results obtained using this modelling agree excellently with Brendel's recently reported experimental results. This enhancement of the optical absorptance in a thin Si film with nanovoids has potential application in different devices, e.g. thin Si solar cells. The realization of nanovoids can be achieved by high temperature annealing of double-layer porous silicon, i.e. a quasi-monocrystalline porous silicon (QMPS) layer.

Document Type: Research article

DOI: 10.1088/0957-4484/16/9/023

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$42.18 plus tax      Refund Policy

 

OR

Back to top

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages.
Page Help Click here for Page Help
Shopping cart
Tools
Sign in






Need to register?
Sign up here
Text size: A | A | A | A