Temperature Dependent Optical and Morphological Properties of Sb2Te3 Thin Films

Sb2Te3 thin films of different temperature ranging from room temperature to 200°C were prepared on glass substrate by thermal evaporation method. The effects of temperature on optical and morphological properties of thin films were studied. AFM images indicated crystalline nature of Sb2Te3. The optical properties exhibited a decreasing trend of band gap from 1.24eV to 1.06eV with increase in temperature. Transmittance decreased as the temperature was increased and displayed no transmittance in the visible range at 200°C. Surface roughness decreased up to 150°C after which it increased

Optimization of thickness of Sb2Te3 thin film as back contact for CdTe thin film solar cells

Sb2Te3 thin films of different thickness ranging from 100 to 500 nm were prepd. on glass substrate by thermal evapn. method. The effects of thickness on structural, optical and elec. properties of thin films were studied. XRD revealed that grain size increases from 1.1nm to 98.7 nm with increase in film thickness. The internal strain and dislocation d. decreased with increase in film thickness. The optical band gap decreases from 1.3 to 0.9 eV with increase in film thickness. AFM images indicated cryst. nature of Sb2Te3. Surface roughness increased up to 400nm after which it decreased. The resistivity decreases with increase in thickness at room temp. ranging from 2.9×10-​3 to 1.35×10-​4 Ωcm. The work function and barrier height decreases as the film thickness increases from 5.45 to 5.05eV and barrier height from 0.3 to -​0.1eV. The results elucidate that Sb2Te3 back contact of 400 nm thickness is ideal and efficient to be used in CdTe solar cell

Optical and structural properties of CdS​/ZnSe bi-​layer thin films prepared by e-​beam technique

Single- and bi-​layer thin films of Cadmium Sulfide (CdS) and Zinc Selenide (ZnSe) were prepd. on glass and ITO​/Glass substrates by e-​beam technique. Spectral transmittance of bi-​layer thin film showed red shift with prolonged interference effect. The decrease in Urbach tail of bi-​layer thin film signifies the decreased band gap with increased grain size. Single layer CdS film has prominent (002) hexagonal peak where as bi-​layer thin film confirm with (002) hexagonal and (111) cubic peaks of CdS and ZnSe resp. CdS grain size was found to be 14.5, 17.1, and 33.1 nm on glass, ITO​/Glass and ZnSe​/ITO​/Glass substrates resp