Preparation and formation mechanism of CdS nano-films via chemical bath deposition
Frontiers of Chemistry in China - Tập 3 - Trang 18-22
Tóm tắt
CdS semiconductor nano-films were grown on ITO glass substrates by means of chemical bath deposition (CBD), with Cd(NO3)2 as Cd ion and (NH2)2CS as S ion sources. The concentration of Cd ions, deposition temperature, deposition time and post-treatment temperature have an impact on the formation of CdS nano-films. UV-vis absorption spectrum and atomic force microscope (AFM) images indicated that the change of concentration and post-treatment temperature may adjust the band-gap of CdS to obtain stable, homogeneous and compact films. Formation mechanism of the crystal nucleus and CdS film was also discussed. Active sites on the surface of ITO are critical to the formation of the crystal nucleus and a uniform and compact CdS nano-film. The active site and crystal nucleus are formed due to the comprehensive effect of electricity, thermodynamics and chemistry.
Tài liệu tham khảo
Rao A P, Pajonk G M, Rao V, Effect of pH, aging, and drying on the size of CdS nanocrystallites, monolithicity, and transparency of nanocrystalline CdS-Doped silica xerogels. J Mater Syn Proce, 2001, 9: 11–18
Vigil O, Rodriguez Y, Zelaya-Angel O, Vàzquez-Lòpez C, Morales-Acevedo A, Vàzquez-Luna J G, Properties of CdS thin films chemically deposited in the presence of a magnetic field. Thin Solid Films, 1998, 322: 329–333
Yamaguchi K, Yoshida T, Sugiura T, Minoura H, A novel approach for CdS thin-film deposition: electrochemically induced atom-by-atom growth of CdS thin films from acidic chemical bath. J Phys Chem B, 1998, 102: 9677–9686
Ichimaura M, Goto F, Arai E, Structural and optical characterization of CdS films grown by photochemical deposition. J Appl Phys, 1999, 85: 7411–7417
Lozada-Morales R, Zelaya-Angel O, Torres-Delgado G, On the yellow-band emission in CdS films. Appl Phys A, 2001, 73: 61–65
Oliva A I, Solís-Canto O, Castro-Rodríguez R, Quintana P, Formation of the band gap energy on CdS thin films growth by two different techniques. Thin Solid Films, 2001, 391: 28–35
Martínez M A, Guillén C, Herrero J, Morphological and structural studies of CBD-CdS thin films by microscopy and diffraction techniques. Appl Surf Sci, 1998, 136: 8–16
Yang J, Tian H Z, Wang C X, Fabrication of high-quality transparent ZnO/Diamond heterojunction. Journal of Julin University (Science Edition), 2006, 4(3): 460–464 (in Chineses)
Allen P B, Cardona M, Theory of the temperature dependence of the direct gap of germanium. Phys Rev B, 1981, 23(4): 1495–1505
Zhang H, Yang D R, Ma X Y, Que D L, CdS thin films fabricated by chemical bath deposition. Acta Energiae Solaris Sinica, 2003, 24(1): 1–4 (in Chineses)