Structural, optical and electrical properties of spray pyrolytically deposited thin films of CuInS2

Abstract

CuInS 2 is a promising chalcopyrite semiconducting material for solar cell fabrication. Using aqueous solutions of cupric chloride, indium trichloride and thiourea, we deposited thin CuInS 2 films on glass at 350°C and studied their structural, optical and electrical properties. From the XRD pattern the chalcopyrite structure of these films was confirmed. The films were polycrystalline. The grain size estimated from scanning electron mierographs was found to be of the order of 1/~m. Resistivity of the film was measured for temperatures ranging from 77 to 473 K. Band gap values were determined from optical transmission data. Hall mobility and carrier concentration at room temperature were calculated using Van der Pauw-Hall method.

Variation of some physical properties of CuInS2 films by substrate temperature

“…However, many researchers [20,33,34,21] using spray pyrolysis and different techniques, obtained a single phase of tetragonal chalcopyrite crystal of CuInS 2 thin films.Our calculated values of lattice parameter well agree with results reported by other workers [20, 34 and 35]. The grain size (D) was calculated using Debye-Scherror formula from the full width at half maxima (FWHM) [36] [22] [19].…”

“…Ours values well agreed with Kazmerski [50] and other researchers [51] for vacuum evaporation method. They observed Hall mobility in the range 10-30 cm 2 V -1 s -1 [6]. By Wahab et al [32] [43] were fabricates CuInS 2 thin films material by thermal evaporation method and studied their electrical dc conductivity and activation energy in the temperature range between 150-300 0 C. The conductivity values were between 76.…”

“…CuInS 2 is one of the I-III-VI 2 chalcopyrite-type mixed crystal semiconductor. CuInS 2 as an absorber layer is very promising for thin film photovoltaic applications [3], which matches well with the solar spectrum,its high absorption coefficient of approximately 10 5 cm -1 and its direct band gap energy obtained from 1.40 -1.53 eV [3][4][5] and high absorption coefficient [6] and its controllable conduction type. In the recent years the ternary group compounds have high conversion efficiency that exceeds 12 to 19 %.…”

“…Several techniques have been investigated to prepare CuInS 2 thin films. Thin films of ternary compound have been prepared by several methods such as evaporation [7][8][9], electro-deposition [11] [12], chemical bath deposition [13] and spray pyrolysis [5,6,[14][15][16][17][18][19][20][21][22]. Electronic structures were reported by Jaffe and Junger [23], there are fundamental role to deep study with support (ideal) to all new researchers.…”