I got a message for missing { inserted in caption
\caption{Schematic of band alignment due to the contact formation between
metal and n-type semiconductor. Here, $\phi_{MS}$ is the difference of
metal work function ($\phi_M$) and semiconductor work function ($\phi_S$),
E$_F$ is the Fermi energy level of metal, E$_F$ is the Fermi energy level
of semiconductor, E$_C$ is the the conduction band (CB) minima, E$_V$ is
the valence band (VB) maxima and $\phi_S^'$ is Shottky barrier
height [Piprek\cite{AB2}].}
and .lof file open with text
\addvspace {10\p@ }
\contentsline {figure}{\numberline {1.1}{\ignorespaces Schematic of band
alignment due to the contact formation between metal and n-type
semiconductor. Here, $\phi _{MS}$ is the difference of metal work function
($\phi _M$) and semiconductor work function ($\phi _S$), E$_F$ is the
Fermi energy level of metal, E$_F$ is the Fermi energy level of
semiconductor, E$_C$ is the the conduction band (CB) minima, E$_V$ is the
valence band (VB) maxima and $\phi _S^'$ is Shottky barrier height
[Piprek\cite {AB2}].}}{6}{figure.1.1}
Can any body help whats wrong in this
! to?in a code section on the question. probably you have a fragile command in the caption that needs\protect, which could be some definitions of\cite` but the fragments you show do not show any obvious error – David Carlisle Nov 03 '15 at 21:40E$_V$and$\phi_S^'$rather than$\mathrm{E}_V$and$\phi'_S$? – David Carlisle Nov 03 '15 at 21:43