Title: Enhanced light absorption of solar cells and photodetectors by diffraction

Abstract

Enhanced light absorption of solar cells and photodetectors by diffraction is described. Triangular, rectangular, and blazed subwavelength periodic structures are shown to improve performance of solar cells. Surface reflection can be tailored for either broadband, or narrow-band spectral absorption. Enhanced absorption is achieved by efficient optical coupling into obliquely propagating transmitted diffraction orders. Subwavelength one-dimensional structures are designed for polarization-dependent, wavelength-selective absorption in solar cells and photodetectors, while two-dimensional structures are designed for polarization-independent, wavelength-selective absorption therein. Suitable one and two-dimensional subwavelength periodic structures can also be designed for broadband spectral absorption in solar cells and photodetectors. If reactive ion etching (RIE) processes are used to form the grating, RIE-induced surface damage in subwavelength structures can be repaired by forming junctions using ion implantation methods. RIE-induced surface damage can also be removed by post RIE wet-chemical etching treatments.

Inventors:

Zaidi, Saleem H.; Gee, James M.

Issue Date:

Tue Feb 22 00:00:00 EST 2005

Research Org.:

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1175245

Patent Number(s):

6858462

Application Number:

09/834,308

Assignee:

Gratings, Inc. (Albuquerque, NM)

Patent Classifications (CPCs):

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

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H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES

H01L31/02363 - {of the semiconductor body itself, e.g. textured active layers}
H01L31/1804 - {comprising only elements of Group IV of the Periodic System}

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

Y02E10/547 - Monocrystalline silicon PV cells

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02P - CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

Y02P70/50 - Manufacturing or production processes characterised by the final manufactured product

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DOE Contract Number:  

AC04-94AL85000

Resource Type:

Patent

Country of Publication:

United States

Language:

English

Subject:

14 SOLAR ENERGY