\Section[
    \eng{Surface-Photovoltage}
    \ger{Oberflächen-Photospannung}
]{spv}
    Mechanisms: 
    \begin{formula}{scr}
        \desc{Space-charge regions}{}{}
        % \desc[german]{}{}{}
        \ttxt{
            \eng{Under illumination, the potential of a space charge region is reduced through the separation of photogenerated charge carriers}
        }
    \end{formula}
    \begin{formula}{dember}
        \desc{Dember-Photovoltage}{}{\QtyRef{diffusion_coefficient}}
        % \desc[german]{}{}{}
        \ttxt{
            \eng{Usually electrons diffuse faster than holes ($D_\txe > D_\txh$) \Rightarrow charge carrier separation}
        }
    \end{formula}

    \begin{formula}{asymmetric_charge_transfer}
        \desc{Asymmetric charge transfer}{}{}
        % \desc[german]{}{}{}
        \ttxt{
            \eng{Asymmetric transfer rates from bulk to surface states and vice versa leads to charge carrier separation}
        }
    \end{formula}
    \begin{formula}{exciton_dissociation}
        \desc{Exciton dissociation}{Important in organic semiconductors with conjugated molecules}{}
        % \desc[german]{}{}{}
        \ttxt{
            \eng{Excitons dissociate at donor-acceptor heterojunctions and the electron is transferred to the acceptor}
        }
    \end{formula}
    \begin{formula}{surface_dipoles}
        \desc{Surface dipoles}{}{}
        % \desc[german]{}{}{}
        \ttxt{
            \eng{Light can excite electrons, which are then attracted to one part of the molecule. This leads to an orientation of surface dipoles}
        }
    \end{formula}
