Impact of Mg Doping on Performances of CuGaO2 Based p-Type Dye-Sensitized Solar Cells

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• 作者：Adèle Renaud ; Laurent Cario ; Philippe Deniard ; Eric Gautron ; Xavier Rocquefelte ; Yann Pellegrin ; Errol Blart ; Fabrice Odobel ; Stéphane Jobic
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：January 9, 2014
• 年：2014
• 卷：118
• 期：1
• 页码：54-59
• 全文大小：360K
• ISSN：1932-7455

文摘

p-Type dye solar cells (p-DSSCs) have been receiving much attention due to their potential role in the elaboration of future tandem dye solar cells with a photoanode and a photocathode built upon n-type and a p-type semiconductors, respectively. So far, NiO appears as the most widely used semiconductor in p-DSSCs. Yet this material suffers from several drawbacks, e.g., a low electrical conductivity and a low redox potential that limit the photovoltaic performances. In that framework, delafossite compounds may be regarded as appropriate substitutes of nickel oxide in relation to their intrinsic optoelectronic properties. Here we report on the nanostructuration of CuGaO₂ and its Mg doped derivatives via hydrothermal conditions with Pluronic P123 as surfactant. It appears that a low amount of magnesium helps in preparing samples with higher specific surface areas and stimulates enhanced conversion efficiencies. Beyond a given Ga/Mg substitution rate, a new Cu_1-x(Ga,Mg)O₂ phase is formed that contains a large amount of Cu vacancies and of structural defects. This new phase shows lower photovoltaic performances compared to those for slightly doped derivatives which suggests that Cu vacancies and/or structural defects limit the mean free path of holes within the photocathode.