A team of researchers at the University of Notre Dame, led by Prashant V. Kamat, has developed a semi-conductive paint that turns surfaces on which it is applied into solar cells.
The solar paint is described in U.S. Patent Application Publication No. 2009/0114273 (‘273 Application), entitled “Nanomaterial Scaffolds for Electron Transport”.
Single wall carbon nanotubes (SWCNT) create the scaffold architecture, which allows electrons to move more efficiently than prior art vis-a-vis nanoparticles or quantum dots.
The nanoparticles are coated in titanium dioxide and either cadmium sulfide or cadmium senenide. The particles are then suspended in a water and alcohol mixure to form a paste.
Figure 1 depicts the improvement made in the ‘273 Application (Figure 1B) over the prior art (Figure 1A). Figures 10A and 10B depict random electron transport versus direct electron transport utilizing the nanotubes described in the ‘273 Application.
According to the ‘273 Application, because of the SWCNT’s special properties, it can boost the solar paint’s photoconversion efficiency:
The unique electrical and electronic properties, wide electrochemical stability window, and high surface area render SWCNT beneficial as a scaffold to anchor light harvesting assemblies. In accordance with an embodiment, the electron accepting ability of semiconducting SWCNT thus offers an opportunity to facilitate electron transport and thus increase the photoconversion efficiency of nanostructure semiconductor based solar cells.
See Kamat’s article about the paint, dubbed “Sun-Believable,” here.
The possibilities surrounding an inexpensive and efficient solar paint are clear, as it could be applied on everyday surfaces like fences and homes to generate electricity. This product could be a huge breakthrough for renewable energy production.
See a short video about how solar paint works here.