Nanocolumnar CuInS2 thin films by glancing angle deposition

Copper indium disulfide was deposited on native glass substrates using glancing angle deposition with and without substrate rotation. The growth mechanism and film morphology are explored in detail. Due to the shadowing effect, the glancing angle deposition (GLAD) technique can produce nanorods tilted toward the incident deposition flux. During depositions, the substrate temperature was maintained at 200 °C. The evaporated atoms arrive at the growing interface at a fixed angle θ measured from the substrate normal. When the substrate is rotated, the rotational speeds ω are fixed at 0.033 and 3.33 rev s−1. The films have been characterized using X-ray diffraction measurements, atomic force microscopy observations (AFM) and spectrophotometer measurements (reflection and transmission). It was demonstrated that structure and related properties are strongly influenced by θ and the rotational speed ω. In the case of absence of the substrate rotation, the AFM pictures show that the structure of the resulting film consists of nanocolumns that are progressively inclined towards the evaporation source as the incident angle was increased. When the substrate is rotated during deposition at an angle of 80°, the nanocolumns take the wires forms only for elevated rotational speeds ω. These observations show that wires are highly textured and have random orientations in the plane of the substrate.