  We report the realization and characterization using coherent population
trapping (CPT) spectroscopy of an octadecyltrichlorosilane (OTS)-coated
centimeter-scale Cs vapor cell. The dual-structure of the resonance lineshape,
with presence of a narrow structure line at the top of a Doppler-broadened
structure, is clearly observed. The linewidth of the narrow resonance is
compared to the linewidth of an evacuated Cs cell and of a buffer gas Cs cell
of similar size. The Cs-OTS adsorption energy is measured to be (0.42 $\pm$
0.03) eV, leading to a clock frequency shift rate of $2.7\times10^{-9}/$K in
fractional unit. A hyperfine population lifetime, $T_1$, and a microwave
coherence lifetime, $T_2$, of 1.6 and 0.5 ms are reported, corresponding to
about 37 and 12 useful bounces, respectively. Atomic-motion induced Ramsey
narrowing of dark resonances is observed in Cs-OTS cells by reducing the
optical beam diameter. Ramsey CPT fringes are detected using a pulsed CPT
interrogation scheme. Potential applications of the Cs-OTS cell to the
development of a vapor cell atomic clock are discussed.
