Zhou Nanjia, Kim Myung-Gil, Loser Stephen, Smith Jeremy, Yoshida Hiroyuki, Guo Xugang, Song Charles, Jin Hosub, Chen Zhihua, Yoon Seok Min, Freeman Arthur J, Chang Robert P H, Facchetti Antonio, Marks Tobin J
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208; Argonne Northwestern Solar Energy Research Center, Northwestern University, Evanston, IL 60208;
Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, IL 60208;
Proc Natl Acad Sci U S A. 2015 Jun 30;112(26):7897-902. doi: 10.1073/pnas.1508578112. Epub 2015 Jun 15.
In diverse classes of organic optoelectronic devices, controlling charge injection, extraction, and blocking across organic semiconductor-inorganic electrode interfaces is crucial for enhancing quantum efficiency and output voltage. To this end, the strategy of inserting engineered interfacial layers (IFLs) between electrical contacts and organic semiconductors has significantly advanced organic light-emitting diode and organic thin film transistor performance. For organic photovoltaic (OPV) devices, an electronically flexible IFL design strategy to incrementally tune energy level matching between the inorganic electrode system and the organic photoactive components without varying the surface chemistry would permit OPV cells to adapt to ever-changing generations of photoactive materials. Here we report the implementation of chemically/environmentally robust, low-temperature solution-processed amorphous transparent semiconducting oxide alloys, In-Ga-O and Ga-Zn-Sn-O, as IFLs for inverted OPVs. Continuous variation of the IFL compositions tunes the conduction band minima over a broad range, affording optimized OPV power conversion efficiencies for multiple classes of organic active layer materials and establishing clear correlations between IFL/photoactive layer energetics and device performance.
在各类有机光电器件中，控制电荷在有机半导体 - 无机电极界面处的注入、提取和阻挡，对于提高量子效率和输出电压至关重要。为此，在电接触和有机半导体之间插入工程化界面层（IFL）的策略显著提升了有机发光二极管和有机薄膜晶体管的性能。对于有机光伏（OPV）器件而言，一种电子柔性IFL设计策略，即在不改变表面化学性质的情况下逐步调整无机电极系统与有机光活性组件之间的能级匹配，将使OPV电池能够适应不断更新换代的光活性材料。在此，我们报告了化学/环境稳定性良好、通过低温溶液法制备的非晶透明半导体氧化物合金铟镓氧化物（In - Ga - O）和镓锌锡氧化物（Ga - Zn - Sn - O）作为倒置OPV的IFL的应用。IFL成分的连续变化可在很宽的范围内调节导带最小值，为多类有机活性层材料提供优化的OPV功率转换效率，并在IFL/光活性层能量学与器件性能之间建立明确的相关性。
