ORGANIC-INORGANIC HYBRID MATERIAL AND METHOD FOR SILICON SURFACE PASSIVATION

• US 20190319161A1
• Filed: 06/22/2017
• Published: 10/17/2019
• Est. Priority Date: 07/11/2016
• Status: Active Grant

• Current Assignee: Institutt For Energiteknikk, Universidad Complutense De Madrid
• Original Assignee: Institutt For Energiteknikk
• Inventors: CREMADES RODRIGUEZ, Ana, YOU, Chang Chuan, MAESTRE VAREA, David, STENSRUD MARSTEIN, Erik, VASQUEZ VILLANUEVA, Geraldo Cristian, HAUG, Halvard, PIQUERES DE NORIEGA, Javier, GONZALEZ CALBET, Jose Maria, RAMIREZ CASTELLANOS, Julio, TAENO GONZALEZ, Maria, GARCIA TECEDOR, Miguel, KARAZHANOV, Smagul
• Granted Patent: US 10,811,558 B2
• Time in Patent Office: Days
• CPC Class Codes: C09D 165/00 Coating compositions based on macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C09D107/00 - C09D157/00, C09D161/00 take precedence; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: C09D 7/45 Anti-settling agents
• CPC Class Codes: C09D 7/61 inorganic
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: H01L 31/04 adapted as photovoltaic [PV] conversion devices testing thereof during manufacture H01L22/00; testing thereof after manufacture H02S50/10
• CPC Class Codes: H01L 31/1868 Passivation
• CPC Class Codes: H10K 71/12 using liquid deposition, e.g. spin coating
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

A relevant technological challenge is the low cost and abundant materials development for silicon surface passivation for applications in optoelectronic devices, in particular in solar cells by scalable industrial methods. In the present invention, a new hybrid material comprising PEDOT:PSS and transparent conducting oxide nanostructures is developed and a method is proposed to fabricate the composite material that passivates well the silicon surface to be used by means of a thin composite film of thickness below 200 nm.

Claims

1. Hybrid organic-inorganic material consisting of an organic conductor polymer matrix and transparent conducting oxide nanostructures as filler, where the conductive polymer is PEDOT:

PSS and the nanostructures are dispersed in the polymer in a ratio of 0.1-10% wt., preferably of 0.25%-5% wt.

2. The hybrid organic-inorganic material, as claimed in claim 1, having tin and/or titanium oxide nanoparticles undoped or doped with Cr, Al, or Li with a cationic percentage range of 1 to 40%, preferably 1 to 30%, and the nanoparticles have sizes between 1-65 nm, preferably 5-50 nm.

3. The hybrid organic-inorganic material, as claimed in claim 1, having tin and/or titanium oxide nanowires undoped or doped with Cr, Al, or Li with a preferred cationic percentage range of 1 to 40%, preferably 1 to 30%, and the nanowires have sections of up to a 100 nm and lengths of up to 1000 nm.

4. The hybrid organic-inorganic material, as claimed in claim 2, having a mixture with controlled ratios of the tin and/or titanium oxide nanoparticles and/or the tin and/or titanium oxide nanowires.

5. The hybrid organic-inorganic material, as claimed in claim 1, having other filler such as carbon nanotubes, Si nanoparticles or nanowires, Al₂O₃ nanoparticles or nanowires, and SiN_x nanoparticles or nanowires, or a mixture thereof.

6. The hybrid organic-inorganic material, as claimed in claim 1, having Ethylene Glycol as dispersant added to the dispersion of the organic conductor.

7. A method for fabricating a hybrid composite containing an organic conductor as host and semiconducting nanostructures as filler, comprising at least the steps of:

Providing an aqueous dispersion of a conductive polymer.

Providing transparent conducting oxide nanostructures with controlled size and doping by techniques such as hydrolysis, modified Pechini method or vapour-solid method.

Adding the nanostructures in the ratios lower than 10% wt, preferably in a ratio 0.25-5% wt., at the aqueous dispersion under ultra-sonication.

8. Passivation method comprising the deposition of the hybrid composite by the spin coating technique of one or several layers of the hybrid material over a substrate, and subsequent water removal.

11. Passivation method as claimed in claim 8, where the substrate to be passivated consists of untreated type p or type n silicon.

12. Passivation method as claimed in claim 8, where the substrate to be passivated consists of type p or type n silicon coated with silicon dioxide.

13. Passivation method as claimed in claim 12, having an IPA treatment of the silicon substrate to increase the hydrophilic character of the substrate.

14. Passivation method as claimed in claim 8, having passivation films containing two or more composite piled layers deposited by spin-coating with a gradient of nanostructure concentrations of different types and materials designed on-demand.

9. Passivation method as claimed in 8, where the water is removed by a thermal treatment, at a temperature range of 100-130°

C., preferably 110-125°

C. during 10 to 30 minutes, preferably 15 to 25 minutes.

10. Passivation method as claimed in 8, where the deposited layer has a thickness below 200 nm, preferably in a range of 90-150 nm.