Microstructural and H2S sensitivity of CBD synthesized CdS thin film: Influence of cobalt doping

Micorstructural and H2S sensitivity of CdS thin film synthesized by chemical bath deposition (CBD) and influence of cobalt are discussed in the present work. X-ray diffraction (XRD) shows cubic structure with an average particle size of ~12.5 nm for CdS and ~15.2 nm for 5% CO:CdS. Selected area electron diffraction (SAED) pattern confirms the cubic structure and TEM shows an average particle size of ~16 nm for CdS. AFM shows enhanced surface roughness due to cobalt incorporation. RMS roughness (Rq) increases from 7.35 nm to 8.02 nm after Co doping. Incorporation of Co was confirmed by EDX. Co doping increases sensitivity to H2S quite significantly from ~56% for CdS to ~72% for 5% Co:CdS at a low operating temperature of 100 °C. Such enhancement of sensitivity due to cobalt incorporation in CdS is reported for the first time to the best of our knowledge.