Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
Nano Lett. 2011 Nov 9;11(11):4953-7. doi: 10.1021/nl202902z. Epub 2011 Oct 17.
Iron pyrite (FeS(2)) is a naturally abundant and nontoxic photovoltaic material that can potentially make devices as efficient as silicon-based ones; however existing iron pyrite photovoltaic devices contain thermodynamically unstable FeS(2) film surfaces that lead to low open circuit voltages. We report the rational synthesis of phase pure, highly crystalline cubic FeS(2) nanocrystals (NCs) using a trioctylphosphine oxide (TOPO) assisted hot-injection method. The synthesized pyrite NC films have excellent air stability over one year. In contrast, obvious surface decomposition was observed on the surface of FeS(2) NCs synthesized without TOPO. A high carrier mobility of 80 cm(2)/(V s) and a strong photoconductivity were observed for the first time for pyrite films at room temperature. Our results indicate that TOPO passivates both iron and sulfur atoms on FeS(2) NC surfaces, efficiently inhibiting surface decomposition.
黄铁矿（FeS2）是一种丰富且无毒的光伏材料，它有潜力让器件的效率与基于硅的器件一样高；然而，现有的黄铁矿光伏器件包含热力学不稳定的 FeS2 薄膜表面，导致开路电压较低。我们报告了使用三辛基氧化磷（TOPO）辅助热注射法合理合成单相纯、高度结晶的立方 FeS2 纳米晶体（NCs）。合成的黄铁矿 NC 薄膜在一年以上的时间内具有极好的空气稳定性。相比之下，在没有 TOPO 的情况下合成的 FeS2 NCs 的表面上观察到明显的表面分解。我们首次在室温下观察到黄铁矿薄膜具有 80 cm2/（V s）的高载流子迁移率和强光电导性。我们的结果表明，TOPO 使 FeS2 NC 表面上的铁和硫原子都钝化，有效地抑制了表面分解。
