Spray on Solar PV

New Energy Technologies Inc. have been promoting a new spray-on, see through solar PV coating which can be applied to glass windows.  Earlier this year they were indicating that around 20 new patent filings have been submitted for their proprietary SolarWindow™ technology.  Last year I reported on one of the early patent filings and the article can be viewed here.  Dr Xiaomei Jiang has been leading this effort with New Energy Technologies under a Sponsored Research Agreement at the University of South Florida (USF).

Two more patent applications have emerged this month from Dr Jiang at USF and they continue to reveal further details of the spray on techniques and solar PV architecture.

US20130255757: ORGANIC PHOTOVOLTAIC ARRAY AND METHOD OF MANUFACTURE

Publication date: 03/10/2013

Inventor(s): JIANG XIAOMEI JANE [US]; LEWIS JASON ERIK [US]

Abstract

The fabrication and characterization of large scale inverted organic solar array fabricated using all-spray process is disclosed, consisting of four layers; ITO-Cs2CO3-(P3HT:PCBM)-modified PEDPT:PSS, on a substrate. With PEDPT:PSS as the anode, the encapsulated solar array shows more than 30% transmission in the visible to near IR range. Optimization by thermal annealing was performed based on single-cell or multiple-cell arrays. Solar illumination has been demonstrated to improve solar array efficiency up to 250% with device efficiency of 1.80% under AM1.5 irradiance. The performance enhancement under illumination occurs only with sprayed devices, indicating device enhancement under sunlight, which is beneficial for solar energy applications. The semi-transparent property of the solar module allows for applications on windows and windshields, indoor applications, and soft fabric substances such as tents, military back-packs or combat uniforms, providing a highly portable renewable power supply for deployed military forces.

US20130263916: ALL SPRAY SEE-THROUGH ORGANIC SOLAR ARRAY WITH ENCAPSULATION

Publication date: 10/10/2013

Inventor(s): LEWIS JASON ERIC [US]; JIANG XIAOMEI JANE [US]

Abstract

An inverted organic solar photovoltaic cell is described that may be fabricated onto rigid or flexible substrates using spray-on technology to apply the various layers of the cell. Indium tin oxide with a thin layer of cesium carbonate functions as the cathode for the novel inverted cells. An active layer of poly-3(hexylthiophene) and [6,6]-phenyl C61-butyric acid methylester having a thickness around 200 nm to 600 nm facilitates a high level of light transmittal through the cell. A modified PEDOT:PSS, made by doping a conductive polymer with dimethylsulfoxide (DMSO), functions as the anode. A method of forming the inverted organic solar photovoltaic cell is also described using gas-propelled spraying to achieve thin layers. After the layers are formed, the cell is sealed using a vacuum and temperature-based annealing and encapsulation with UV-cure epoxy.

Phil’s Comments:

These applications are going through the patent office examination process so it is difficult to comment on the claims until we know what will actually be allowed.  The claims do make reference to spraying and the second application indicates that nitrogen is used as a propellant.

The device is an inverted solar cell design and may be fabricated onto both rigid and flexible substrates. Exemplary substrates include cloth, glass, and plastic. For example, the substrate may be a low alkaline earth boro-aluminosilicate glass.

Two figures from the second application are shown below:

FIG. 1 is a diagram that depicts the modified PEDOT:PSS as it is sprayed onto the substrate through a stainless steel shadow mask with an airbrush. Nitrogen is used as the carrier gas at a pressure of 20 psi.

FIG. 13 is a diagram showing the cross sectional view of the device architecture of an inverted solar array showing series connection

Figure 1 Capture2