  Single crystals of the Bi-Ca-Co-O system have been grown using the flux
method with cooling from 900$\celsius$ and 950$\celsius$, respectively. The
single crystals are characterized by transmission electron microscopy and X-ray
diffraction. The misfit cobaltite
[Ca$_2$Bi$_{1.4}$Co$_{0.6}$O$_4$]$^{RS}$[CoO$_2$]$_{1.69}$ single crystals with
quadruple ($n$=4) rocksalt (RS) layer are achieved with cooling from
900$\celsius$. Such crystal exhibits room-temperature thermoelectric power
(TEP) of 180$\mu$V/K, much larger than that in Sr-based misfit cobaltites with
quadruple RS layer. However, intergrowth of single crystals of quadruple
($n$=4) and triple ($n$=3) RS-type layer-based misfit cobaltites is observed
with cooling from 950$\celsius$. Both of TEP and resistivity were obviously
enhanced by the intergrowth compared to
[Ca$_2$Bi$_{1.4}$Co$_{0.6}$O$_4$]$^{RS}$[CoO$_2$]$_{1.69}$ single crystal,
while the power factor at room temperature remains unchanged.
