Microstructural and H_2S sensitivity of CBD synthesized CdS thin film: Influence of cobalt doping

摘要

Micorstructural and H_2S 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 (R_q) increases from 7.35 nm to 8.02 nm after Co doping. Incorporation of Co was confirmed by EDX. Co doping increases sensitivity to H_2S quite significantly from ～56% for CdS to ～72% for 5% Co : CdS at a low operating temperature of 100 ℃ Such enhancement of sensitivity due to cobalt incorporation in CdS is reported for the first time to the best of our knowledge.