Argonne制作出混合型太阳能电池 瞄准低成本电源
美国能源局Argonne国家实验室的科学家研发了一项新技术，通过制作半导体材料的管，然后在其内直接生长聚合物，来制造太阳能电池。相对比目前商业化工艺下制造的电池，这种方法非常有潜力获得极其便宜的电池。
Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have refined a technique to manufacture solar cells by creating tubes of semiconducting material and then "growing" polymers directly inside them. The method has the potential to be significantly cheaper than the process used to make today’s commercial solar cells.
Because the production costs of today's generation of solar cells prevent them from competing economically with fossil fuels, Argonne researchers are working to re-imagine the solar cell's basic design. Most current solar cells use crystalline silicon or cadmium telluride, but growing a high-purity crystal is energy- and labor-intensive, making the cells expensive.
This computer-generated image shows nanotubes, 10,000 times smaller than the width of a human hair, which comprise a new technique developed at Argonne for "growing" solar cells.
The next generation, called hybrid solar cells, uses a blend of cheaper organic and inorganic materials. To combine these materials effectively, Argonne researchers created a new technique to grow organic polymers directly inside inorganic nanotubes.
At its most basic level, solar cell technology relies on a series of processes initiated when photons, or particles of light, strike semiconducting material. When a photon hits the cell, it excites one electron out of its initial state, leaving behind a "hole" of positive charge.
An electron microscope image of electrochemically grown TiO2 nanotubes. 10,000 times smaller than the width of a human hair, the tubes are filled with organic polymer in a new technique developed at Argonne for "growing" solar cells with the potential to be cheaper than current solar cells.
Hybrid solar cells contain two separate types of semiconducting material: one conducts electrons, the other holes. At the junction between the two semiconductors, the electron-hole pair gets pulled apart, creating a current.
In the study, Argonne nanoscientist Seth Darling and colleagues at Argonne and the University of Chicago had to rethink the geometry of the two materials. If the two semiconductors are placed too far apart, the electron-hole pair will die in transit. However, if they're packed too closely, the separated charges won’t make it out of the cell.
In designing an alternative, scientists paired an electron-donating conjugated polymer with the electron acceptor titanium dioxide (TiO2).
