Law Matt, Greene Lori E, Johnson Justin C, Saykally Richard, Yang Peidong
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Nat Mater. 2005 Jun;4(6):455-9. doi: 10.1038/nmat1387. Epub 2005 May 15.
Excitonic solar cells-including organic, hybrid organic-inorganic and dye-sensitized cells (DSCs)-are promising devices for inexpensive, large-scale solar energy conversion. The DSC is currently the most efficient and stable excitonic photocell. Central to this device is a thick nanoparticle film that provides a large surface area for the adsorption of light-harvesting molecules. However, nanoparticle DSCs rely on trap-limited diffusion for electron transport, a slow mechanism that can limit device efficiency, especially at longer wavelengths. Here we introduce a version of the dye-sensitized cell in which the traditional nanoparticle film is replaced by a dense array of oriented, crystalline ZnO nanowires. The nanowire anode is synthesized by mild aqueous chemistry and features a surface area up to one-fifth as large as a nanoparticle cell. The direct electrical pathways provided by the nanowires ensure the rapid collection of carriers generated throughout the device, and a full Sun efficiency of 1.5% is demonstrated, limited primarily by the surface area of the nanowire array.
激子太阳能电池，包括有机、有机-无机杂化和染料敏化电池（DSC），是实现廉价大规模太阳能转换的有前景的器件。DSC是目前最有效且稳定的激子光电池。该器件的核心是一层厚纳米颗粒薄膜，它为光捕获分子的吸附提供了大表面积。然而，纳米颗粒DSC依靠陷阱限制扩散进行电子传输，这是一种缓慢的机制，会限制器件效率，尤其是在较长波长下。在此，我们介绍一种染料敏化电池，其中传统的纳米颗粒薄膜被密集排列的定向结晶ZnO纳米线所取代。纳米线阳极通过温和的水相化学合成，其表面积高达纳米颗粒电池的五分之一。纳米线提供的直接电通路确保了整个器件中产生的载流子的快速收集，并且展示了1.5%的全日照效率，主要受纳米线阵列表面积的限制。
