Raymakers Jorne, Krysova Hana, Artemenko Anna, Čermák Jan, Nicley Shannon S, Verstappen Pieter, Gielen Sam, Kromka Alexander, Haenen Ken, Kavan Ladislav, Maes Wouter, Rezek Bohuslav
UHasselt - Hasselt University, Institute for Materials Research (IMO), IMEC vzw, IMOMEC Agoralaan 1, 3590 Diepenbeek Belgium
J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences Dolejskova 3, 18223 Prague 8 Czech Republic.
RSC Adv. 2018 Sep 26;8(58):33276-33290. doi: 10.1039/c8ra07545j. eCollection 2018 Sep 24.
Improving the performance of p-type photoelectrodes represents a key challenge toward significant advancement in the field of tandem dye-sensitized solar cells. Herein, we demonstrate the application of boron-doped nanocrystalline diamond (B:NCD) thin films, covalently functionalized with a dithienopyrrole-benzothiadiazole push-pull chromophore, as alternative photocathodes. First, a primary functional handle is introduced on H-terminated diamond electrochemical diazonium grafting. Afterwards, Sonogashira cross-coupling and Cu(i) catalyzed azide-alkyne cycloaddition (CuAAC) reactions are employed to attach the chromophore, enabling the comparison of the degree of surface functionalization and the importance of the employed linker at the diamond-dye interface. X-ray photoelectron spectroscopy shows that surface functionalization CuAAC results in a slightly higher chromophore coverage compared to the Sonogashira cross-coupling. However, photocurrents and photovoltages, obtained by photoelectrochemical and Kelvin probe measurements, are approximately three times larger on photocathodes functionalized Sonogashira cross-coupling. Surface functionalization Sonogashira cross-coupling is thus considered the preferential method for the development of diamond-based hybrid photovoltaics.
提高p型光电极的性能是串联染料敏化太阳能电池领域取得重大进展的关键挑战。在此，我们展示了用二噻吩并吡咯-苯并噻二唑推挽发色团共价功能化的硼掺杂纳米晶金刚石（B:NCD）薄膜作为替代光阴极的应用。首先，通过电化学重氮盐接枝在氢终止的金刚石上引入一个主要功能手柄。之后，采用Sonogashira交叉偶联和铜（I）催化的叠氮化物-炔烃环加成（CuAAC）反应连接发色团，从而能够比较表面功能化程度以及在金刚石-染料界面处所用连接基的重要性。X射线光电子能谱表明，与Sonogashira交叉偶联相比，通过CuAAC进行表面功能化会导致发色团覆盖率略高。然而，通过光电化学和开尔文探针测量获得的光电流和光电压在通过Sonogashira交叉偶联功能化的光阴极上大约大三倍。因此，Sonogashira交叉偶联表面功能化被认为是开发基于金刚石的混合光伏器件的优先方法。
