Nanostructured films and related methods

• US 9,057,144 B2
• Filed: 07/29/2011
• Issued: 06/16/2015
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah Research Foundation (State of Utah)
• Inventors: Tiwari, Ashutosh, Snure, Michael, Karmarkar, Makarand
• Primary Examiner(s): Landau, Matthew
• Assistant Examiner(s): Anya, Igwe U
• Application Number:
  US13/813,022
• Publication Number:
  US 20130161614A1
• Time in Patent Office: 1,418 Days
• Field of Search: 257/43, 438/73
• US Class Current: 1/1
• CPC Class Codes: C25D 11/02 Anodisation
• CPC Class Codes: C25D 11/26 of refractory metals or alloys based thereon
• CPC Class Codes: C25D 21/10 Agitating of electrolytes; Moving of racks
• CPC Class Codes: C25D 5/02 Electroplating of selected surface areas
• CPC Class Codes: H01G 9/2031 comprising titanium oxide, e.g. TiO2 H01G9/2036 takes precedence
• CPC Class Codes: H01G 9/2036 comprising mixed oxides, e.g. ZnO covered TiO2 particles
• CPC Class Codes: H01G 9/2059 comprising an organic dye as the active light absorbing material, e.g. adsorbed on an electrode or dissolved in solution
• CPC Class Codes: H01L 31/032 including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312
• CPC Class Codes: H01M 14/005 Photoelectrochemical storage cells light sensitive devices H01G9/20, semiconductors sensitive to light H01L31/00
• CPC Class Codes: H10K 85/344 comprising ruthenium
• CPC Class Codes: Y02E 10/542 Dye sensitized solar cells

Abstract

Nanostructured films including a plurality of nanowells, the nanowells having a pore at the top surface of the film, the pore defining a channel that extends downwardly towards the bottom surface of the film are provided. Also provided are methods including exposing a growth substrate to an anodizing bath, applying ultrasonic vibrations to the anodizing bath, and generating a current through the anodizing bath to form the nanostructured film. The nanostructured films may be formed from TiO₂ and may be used to provide solid state dye sensitized solar cells having high conversion efficiencies.

Claims

1. A method of forming a nanostructured film, the method comprising:

providing an anode electrically coupled to a cathode through an anodizing bath, wherein the anode comprises a growth substrate, the anodizing bath comprising an electrolyte solution,

applying ultrasonic vibrations to the anodizing bath, and generating a current through the anodizing bath during the application of the ultrasonic vibrations to form the nanostructured film from the growth substrate,

wherein the current is generated by applying a voltage across the growth substrate and the cathode, the cathode having a surface roughness in the range of from about 200 nm to about 5 μ

m, and

wherein the nanostructured film comprises a plurality of tubular nanowells, the tubular nanowells each having a pore at the top surface of the nanostructured film, the pore defining a channel that extends from the top surface of the nanostructured film downwardly towards the bottom surface of the nanostructured film.

2. The method of claim 1, wherein the growth substrate is a metal growth substrate and the nanostructured film is a metal oxide nanostructured film.

3. The method of claim 1, wherein the growth substrate is a titanium growth substrate and the nanostructured film is a titanium oxide nanostructured film.

4. The method of claim 1, wherein the amplitude of the ultrasonic vibrations is in the range of from about 1 μ

m to about 500 μ

m.

5. The method of claim 1, wherein the frequency of the ultrasonic vibrations is in the range of from about 15 kHz to about 2000 kHz.

6. The method of claim 1, wherein the amplitude of the ultrasonic vibrations is in the range of from about 1 μ

m to about 500 μ

m;

the frequency of the ultrasonic vibrations is in the range of from about 15 kHz to about 2000 kHz;

the concentration of the electrolyte is in the range from about 0.5 wt % to about 5 wt %;

the temperature of the anodizing bath is in the range from about 5°

C. to about 80°

C.;

the current is generated by applying a voltage in the range of from about 10 V to about 60 V across the growth substrate and a cathode;

the distance between the growth substrate and the cathode is in the range of from about 2.5 cm to about 15 cm; and

the current is generated for a time period in the range of from about 20 minutes to 72 hours.

7. The method of claim 1, wherein one or more of the tubular nanowells have a tapered end.

8. A nanostructured film prepared according to the method of claim 1.